HP Color LaserJet 4500 And 4550 Series Service Manual. Www.s Manuals.com. 4500, Manual

User Manual: Laser Printer HP Color LaserJet 4550 - Service manuals and Schematics, Disassembly / Assembly. Free.

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hp color LaserJet
4550/4500 series
service
manual
achieve
HP Color LaserJet 4550/4550N/4550DN/
4550HDN Printer and HP Color LaserJet 4500/
4500 N/4500 DN Printer
Service Manual _____________
Hewlett-Packard Company
11311 Chinden Boulevard
Boise, Idaho 83714 U.S.A.
© Copyright 2000, Hewlett-Packard
Company
All Rights Reserved. Reproduction,
adaptation, or translation without prior written
permission is prohibited, except as allowed
under the copyright laws.
Part number: C7085-90921
First Edition, October 2000
Warranty
The information contained in this document is
subject to change without notice.
Hewlett-Packard makes no warranty of any
kind with respect to this information.
HEWLETT-PACKARD SPECIFICALLY
DISCLAIMS THE IMPLIED WARRANTY OF
MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE.
Hewlett-Packard shall not be liable for any
direct, indirect, incidental, consequential, or
other damage alleged in connection with the
furnishing or use of this information.
Trademark Credits
Adobe is a trademark of Adobe Systems
Incorporated which may be registered in
certain jurisdictions.
Arial is a U.S. registered trademark of the
Monotype Corporation.
CompuServeTM is a U.S. trademark of
CompuServe, Inc.
ENERGY STAR is a U.S. registered service
mark of the United States Environmental
Protection Agency.
Microsoft® is a U.S. registered trademark of
Microsoft Corporation.
PANTONE® Pantone, Inc.’s check-standard
trademark for color.
PostScript is a trademark of Adobe Systems,
Incorporated, which may be registered in
certain jurisdictions.
TrueType is a U.S. trademark of Apple
Computer, Inc.
UNIX is a registered trademark in the United
States and other countries, licensed
exclusively through X/Open Company
Limited.
Windows, MS Windows, and Windows NT are
U.S. registered trademarks of Microsoft
Corporation.
iii
Conventions
This is a combined Service Manual for both the HP Color LaserJet 4500 series printer and the HP
Color LaserJet 4550 series printer. The HP Color LaserJet 4550 series printer shares most
characteristics of the HP Color LaserJet 4500 series printer, except where stated.
This manual uses the following conventions:
COLoR is used to emphasize items that are important to the material under discussion.
Bold is used for emphasis, particularly in situations where italic type would be confusing.
Italic type is used to indicate related documents or emphasis.
DISPLAY type indicates text as seen on the printer control panel display.
Commands you use on a computer keyboard or on the printer control panel are shown in
[Keycap]. Two examples are [Select], and
[-[Value +].
COURIER type indicates text that you type on a computer keyboard exactly as shown.
Hint Hints are used to suggest an action that might simplify the process.
WWW World Wide Web references give Internet addresses for additional information and information updates.
Note Notes contain important information set off from the text.
CAUTION Caution messages alert you to the possibility of damage to equipment or loss of data.
WARNING! Warning messages alert you to the possibility of personal injury.
iv
Contents v
Contents
1 Printer description
Printer features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Site requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Printer specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Printer assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Media requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Environmental Product Stewardship Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Regulatory statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
2 Service approach
Service approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Parts and supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Warranty statement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
3 Installation and configuration
Unpack the printer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Connecting to a network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Enhanced I/O (EIO) configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
Printer drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
Network configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70
Configuration tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
Setting network security on the printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
4 Printer maintenance
Cleaning the printer and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
Approximate replacement intervals for consumable items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80
Locating consumables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
Replacing consumable items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
DIMM configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
5 Theory of operation
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .102
Basic operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Image formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Toner density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Mechanical system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Paper path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
DC controller subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132
Motors and fans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
Formatter system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
Power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
vi
6 Removal and replacement
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Consumable assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Covers, drawers, and top and front assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Right side assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Left side assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Rear assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Internal assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
7 Troubleshooting
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Troubleshooting process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Printer error troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Paper path troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Image formation troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
HP ColorSmart II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Matching colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Four-color printing (CMYK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Image defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Overhead transparency defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Repetitive defects troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Interface troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Control panel troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Troubleshooting tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Service mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Diagnostics mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
8 Parts and diagrams
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Ordering parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Illustrations and parts lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Alphabetical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Numerical parts list. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Contents vii
List of Figures
Figure 1-1 HP Color LaserJet 4500 family printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Figure 1-2 HP Color LaserJet 4550 series printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Figure 1-3 Model and Serial number information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Figure 1-4 Sample label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Figure 1-5 Space requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Figure 1-6 Front view, HP Color LaserJet 4500 and HP Color LaserJet 4550
(shown with 500-sheet paper feeder and duplex unit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Figure 1-7 Rear view, HP Color LaserJet 4500 (shown with 500-sheet paper feeder and duplex unit) . . . . .26
Figure 1-8 Rear view, HP Color LaserJet 4550 (shown with 500-sheet paper feeder and duplex unit) . . . . .27
Figure 3-1 Package contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Figure 3-2 Parallel cable with a “C” connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
Figure 4-1 Imaging drum life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81
Figure 4-2 OPC life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82
Figure 4-3 Location of consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84
Figure 4-4 Removing the formatter board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98
Figure 4-5 Do not remove the DIMM in slot #4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99
Figure 4-6 Do not remove the DIMM in slot #3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99
Figure 4-7 EDO and SDRAM memory modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .99
Figure 5-1 Basic system operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103
Figure 5-2 Image formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104
Figure 5-3 Primary charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Figure 5-4 Laser exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Figure 5-5 Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106
Figure 5-6 Primary transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107
Figure 5-7 Secondary transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Figure 5-8 Separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .108
Figure 5-9 ITB residual toner cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
Figure 5-10 Waste toner to waste toner reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109
Figure 5-11 Fuser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110
Figure 5-12 Toner density sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111
Figure 5-13 Photosensitive drum cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Figure 5-14 Waste toner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
Figure 5-15 Transfer unit function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113
Figure 5-16 Home position detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114
Figure 5-17 ITB unit life detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115
Figure 5-18 Secondary transfer roller unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116
Figure 5-19 ITB unit contact/separation unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117
Figure 5-20 Toner carousel assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
Figure 5-21 Toner carousel operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119
Figure 5-22 Toner cartridge contact/separation function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119
Figure 5-23 Toner level detection/toner cartridge detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120
Figure 5-24 Laser/scanner operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121
Figure 5-25 Paper jam sensors (shown with the optional 500-sheet paper feeder and duplex
unit installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
Figure 5-26 Tray 2 (cassette) operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123
Figure 5-27 Tray 1 manual feed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Figure 5-28 Laser paper detected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
Figure 5-29 Overhead transparency sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .125
Figure 5-30 Pick-up and feed system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
Figure 5-31 Fusing and delivery unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
Figure 5-32 Reversing and duplex pick-up operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
Figure 5-33 Reversing operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
viii
Figure 5-34 Side registration adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Figure 5-35 Duplex feed roller pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Figure 5-36 DC controller PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Figure 5-37 Motors and fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Figure 6-1 Phillips and Posidriv screwdriver comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Figure 6-2 Top cover removal and replacement (rear view of printer) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Figure 6-3 Left side cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Figure 6-4 Right side cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Figure 6-5 Rear door removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Figure 6-6 Right rear cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Figure 6-7 Drum drawer (top drawer) cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Figure 6-8 Drum drawer (top drawer) cover tabs and levers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Figure 6-9 ITB drawer (middle drawer) cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Figure 6-10 ITB drawer (middle drawer) removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Figure 6-11 Control panel removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Figure 6-12 Front right cover removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Figure 6-13 RFI shield removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Figure 6-14 Laser/scanner assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Figure 6-15 DC controller removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Figure 6-16 Developing PCB removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Figure 6-17 Developing PCB removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Figure 6-18 Top cover switch assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Figure 6-19 Top cover switch assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Figure 6-20 Drum drawer (top drawer) switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Figure 6-21 Drum drawer (top drawer) assembly removal and replacement (1 of 3) . . . . . . . . . . . . . . . . . . 164
Figure 6-22 Drum drawer (top drawer) assembly removal and replacement (2 of 3) . . . . . . . . . . . . . . . . . . 165
Figure 6-23 Drum drawer assembly removal and replacement (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Figure 6-24 Densitometer removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Figure 6-25 Densitometer removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Figure 6-26 Formatter removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Figure 6-27 Formatter pan assembly removal and replacement (1 of 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Figure 6-28 Formatter pan assembly removal and replacement (2 of 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Figure 6-29 Formatter pan assembly removal and replacement (3 of 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Figure 6-30 Formatter pan assembly removal and replacement (4 of 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Figure 6-31 Power supply removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
Figure 6-32 High-voltage power supply removal and replacement (newer version
HP Color LaserJet 4500 and HP Color LaserJet 4550 printers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Figure 6-33 High-voltage power supply removal and replacement (older version
HP Color LaserJet 4500 printers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Figure 6-34 Drum drive assembly removal and replacement (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Figure 6-35 Drum drive assembly removal and replacement (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Figure 6-36 Drum drive assembly removal and replacement (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
Figure 6-37 Large fan removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Figure 6-38 Large fan removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Figure 6-39 Toner level sensor assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Figure 6-40 Carousel drive assembly removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Figure 6-41 Carousel drive assembly removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Figure 6-42 Paper size switch removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Figure 6-43 Switch plate assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Figure 6-44 Paper feed PCB removal and replacement (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Figure 6-45 Paper feed PCB removal and replacement (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Figure 6-46 Paper feed PCB removal and replacement (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
Figure 6-47 Fuser motor removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Figure 6-48 Fuser motor removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Figure 6-49 Paper path motor removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Figure 6-50 Paper pick solenoid removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Figure 6-51 ITB cleaning roller clutch removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Figure 6-52 ITB clutch assembly removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Figure 6-53 ITB clutch assembly removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
ix
Figure 6-54 Transfer roller cam clutch removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192
Figure 6-55 Left side gears removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
Figure 6-56 Left side gears removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .194
Figure 6-57 Large right side fan removal and replacement (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195
Figure 6-58 Large right side fan removal and replacement (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196
Figure 6-59 Left side fan removal and replacement (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .197
Figure 6-60 Left side fan removal and replacement (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198
Figure 6-61 Left side fan removal and replacement (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198
Figure 6-62 Rear paper path assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199
Figure 6-63 Cartridge carousel replacement - formatter pan assembly (1 of 6) . . . . . . . . . . . . . . . . . . . . . .200
Figure 6-64 Cartridge carousel replacement - continuous toner level sensor assembly (2 of 6) . . . . . . . . .201
Figure 6-65 Cartridge carousel replacement - carousel brake (3 of 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201
Figure 6-66 Cartridge carousel replacement - face-down delivery rod (4 of 6) . . . . . . . . . . . . . . . . . . . . . . .202
Figure 6-67 Cartridge carousel replacement - right-side carousel mounting plate (5 of 6) . . . . . . . . . . . . . .202
Figure 6-68 Cartridge carousel replacement - lift out the cartridge carousel (6 of 6) . . . . . . . . . . . . . . . . . .203
Figure 6-69 Paper transport assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .204
Figure 6-70 Paper pick rollers removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205
Figure 6-71 Star wheel assembly removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .206
Figure 6-72 Transfer roller removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .207
Figure 6-73 Cam shaft removal and replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .208
Figure 7-1 Troubleshooting flowchart (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .214
Figure 7-2 Troubleshooting flowchart (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215
Figure 7-3 Jam sensors (shown with the optional 500-sheet paper feeder and duplex unit installed) . . . . .237
Figure 7-4 Jam locations (shown with the optional 500-sheet paper feeder and duplex unit installed) . . . .238
Figure 7-5 Jam locations by error message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239
Figure 7-6 Image formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243
Figure 7-7 Color balance calibration page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251
Figure 7-8 Repetitive defect ruler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .266
Figure 7-9 Imaging drum exposed to light (proportions not to scale) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267
Figure 7-10 HP EIO configuration page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .268
Figure 7-11 4500 series menu map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .271
Figure 7-12 4550 series menu map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .272
Figure 7-13 4500 series (left) and 4550 series (right) printer configuration page . . . . . . . . . . . . . . . . . . . . .287
Figure 7-14 Supplies status page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .290
Figure 7-15 Usage page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .291
Figure 7-16 Hard disk file directory page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .292
Figure 7-17 Service mode menu map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .293
Figure 7-18 HP Color LaserJet 4500 series Service menu map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .294
Figure 7-19 HP Color LaserJet 4550 series Service menu map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .295
Figure 7-20 Registration page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298
Figure 7-21 Location of the engine test button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .306
Figure 7-22 Sensor locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .308
Figure 7-23 Printer solenoids and clutches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .309
Figure 7-24 Printer motors and fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .310
Figure 7-25 Miscellaneous sensors and clutches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .310
Figure 7-26 Intermediate transfer belt sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311
Figure 7-27 Miscellaneous sensors (with tray 1 front cover removed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .312
Figure 7-28 PS6 and PS7 sensor location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .312
Figure 7-29 Miscellaneous switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .313
Figure 7-30 Miscellaneous switches and sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .313
Figure 7-31 PS14 sensor location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .314
Figure 7-32 Miscellaneous parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .314
Figure 7-33 Imaging drum connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .315
Figure 7-34 Rear door interlock switch defeat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .316
Figure 7-35 Right rear fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .316
Figure 7-36 Fuse (F1) and CB101 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .317
Figure 7-37 Fusing assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .317
Figure 7-38 DC controller PCB connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Figure 7-39 Location of connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319
x
Figure 7-40 Location of duplexer and 500-sheet paper feeder connectors . . . . . . . . . . . . . . . . . . . . . . . . . 320
Figure 7-41 500-sheet feeder wiring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Figure 8-1 Assembly location diagram (1 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Figure 8-2 Assembly location diagram (2 of 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Figure 8-3 PCB locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Figure 8-4 External covers, panels, etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
Figure 8-5 Top cover assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Figure 8-6 Internal components (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Figure 8-7 Internal components (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Figure 8-8 Internal components (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Figure 8-9 Developing carousel assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
Figure 8-10 Paper pick-up assembly (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
Figure 8-11 Paper pick-up assembly (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Figure 8-12 Paper pick-up assembly (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Figure 8-13 Upper drawer assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Figure 8-14 MP tray paper pick-up assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
Figure 8-15 250-sheet cassette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Figure 8-16 500-sheet paper feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Figure 8-17 Duplex unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Contents xi
List of Tables
Table 1-1 Printer features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Table 1-2 Model names and numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Table 1-3 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Table 1-4 Environmental specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Table 1-5 Consumable storage requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Table 1-6 Printer dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Table 1-7 Acoustic emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Table 1-8 Supported media specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Table 1-9 Printing on transparencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Table 2-1 Related documentation and software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Table 3-1 Printer security levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Table 4-1 Cleaning the printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
Table 4-2 Approximate replacement interval for consumable items . . . . . . . . . . . . . . . . . . .83
Table 5-1 Toner carousel assembly components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
Table 5-2 Motors, solenoids, sensors, and switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Table 5-3 Motors, solenoids, clutches, and sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .124
Table 5-4 Solenoids, sensors, switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126
Table 5-5 Paper size detection switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
Table 5-6 Fusing and delivery unit components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .128
Table 5-7 Motors, solenoids, and sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .129
Table 5-8 Motor and fan locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133
Table 6-1 Types of screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .141
Table 6-2 Approximate replacement interval for consumable items . . . . . . . . . . . . . . . . . .142
Table 7-1 Pre-troubleshooting checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .213
Table 7-2 Alphabetical printer error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217
Table 7-3 Numerical printer error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226
Table 7-4 HP Color LaserJet 4500 jam locations and associated error messages . . . . . . .239
Table 7-5 HP Color LaserJet 4550 jam locations and associated error messages . . . . . . .240
Table 7-6 Explanation of alternating message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .240
Table 7-7 Image defect table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253
Table 7-9 Defect spacing chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .267
Table 7-10 Communications check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .268
Table 7-11 HP Color LaserJet 4500 Information Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . .273
Table 7-12 HP Color LaserJet 4550 Information Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . .273
Table 7-13 HP Color LaserJet 4500 Paper Handling Menu . . . . . . . . . . . . . . . . . . . . . . . . .274
Table 7-14 HP Color LaserJet 4550 Paper Handling Menu . . . . . . . . . . . . . . . . . . . . . . . . .275
Table 7-15 HP Color LaserJet 4500 Configuration settings . . . . . . . . . . . . . . . . . . . . . . . . .276
Table 7-16 HP Color LaserJet 4550 Configuration settings . . . . . . . . . . . . . . . . . . . . . . . . .277
Table 7-17 HP Color LaserJet 4500 Printing Menu settings . . . . . . . . . . . . . . . . . . . . . . . .278
Table 7-18 HP Color LaserJet 4550 Printing Menu settings . . . . . . . . . . . . . . . . . . . . . . . .279
Table 7-19 HP Color LaserJet 4500 I/O Menu settings . . . . . . . . . . . . . . . . . . . . . . . . . . . .280
Table 7-20 HP Color LaserJet 4550 I/O Menu settings . . . . . . . . . . . . . . . . . . . . . . . . . . . .280
Table 7-21 HP Color LaserJet 4500 Calibration Menu settings . . . . . . . . . . . . . . . . . . . . . .281
Table 7-22 HP Color LaserJet 4550 Calibration Menu settings . . . . . . . . . . . . . . . . . . . . . .281
Table 7-23 HP Color LaserJet 4500 Resets Menu settings . . . . . . . . . . . . . . . . . . . . . . . . .282
Table 7-24 HP Color LaserJet 4550 Resets Menu settings . . . . . . . . . . . . . . . . . . . . . . . . .282
Table 7-25 HP Color LaserJet 4550 Quick Copy Jobs menu . . . . . . . . . . . . . . . . . . . . . . . .283
Table 7-26 HP Color LaserJet 4550 Private/Stored Jobs menu . . . . . . . . . . . . . . . . . . . . .284
Table 7-27 Formatter diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300
Table 7-28 Engine diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302
Table 7-29 Paper path sensors and switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .303
Table 7-30 Paper size settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .304
xii
Table 7-31 Sensor status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Table 7-32 Sensor function and locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Table 7-33 Solenoid and clutch functions and locations . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Table 7-34 Printer motors and fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Table 7-35 Miscellaneous sensors and clutches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Table 7-36 Intermediate transfer belt sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Table 7-37 PS3 and PS4 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Table 7-38 PS6 and PS7 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Table 7-39 Switch description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Table 7-40 SW2, SW5, and PS13 description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Table 7-41 Density sensor location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Table 7-42 Miscellaneous parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Table 7-43 Imaging drum connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Table 7-44 Fuse F1 and CB101 location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Table 7-45 110-volt fusing assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317
Table 8-1 Consumables, accessories, and supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Table 8-2 Types of screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Table 8-3 PCB assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Table 8-4 Printer cover and door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
Table 8-5 Top cover components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Table 8-6 Internal components (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Table 8-7 Internal components (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Table 8-8 Internal components (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Table 8-9 Developing carousel assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Table 8-10 Paper pick-up assembly (1 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
Table 8-11 Paper pick-up assembly (2 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
Table 8-12 Paper pick-up assembly (3 of 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Table 8-13 Upper drawer assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Table 8-14 MP tray paper pick-up assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
Table 8-15 250-sheet cassette . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
Table 8-16 500-sheet paper feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Table 8-17 Duplex unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Table 8-18 Alphabetical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Table 8-19 Numerical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
C7085-90921 Chapter 1 Printer description 13
1Printer description
Chapter contents
Printer features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Model and serial numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power and regulatory information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Site requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Space requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Electrical specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Environmental specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Consumable storage requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Printer specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Printer assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Media requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Selecting print media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Media specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Supported media weights and sizes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Non-supported media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Printing on special media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Environmental Product Stewardship Program. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Regulatory statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
HP Color LaserJet 4500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
HP Color LaserJet 4550 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Laser safety statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Material Safety Data Sheet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Toner safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Laser statement for Finland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
14 Printer description C7085-90921
Printer features
The HP LaserJet 4500 printer family pictured in Figure 1-1 has three models.
The HP LaserJet 4500 printer is the base model; it contains 32 MB of RAM.
The HP LaserJet 4500 N printer is the base model with an HP JetDirect 600N print server
(network card) and 64 MB of RAM.
The HP LaserJet 4500 DN printer is the base model with an HP JetDirect 600N print server
(network card), a 500-sheet paper feeder, a duplex unit, and 64 MB of RAM.
Figure 1-1 HP Color LaserJet 4500 family printers
1HP Color LaserJet 4500 and 4500 N printers
2HP Color LaserJet 4500 DN printer
The HP LaserJet 4550 printer family pictured in Figure 1-2 has four models.
The HP LaserJet 4550 printer is the base model; it includes 64 MB of RAM.
The HP LaserJet 4550N printer is the base model with an HP JetDirect 610N print server
(network card) and 64 MB of RAM.
The HP LaserJet 4550N printer is the base model with an HP JetDirect 610N print server
(network card), a 500-sheet paper feeder, a duplex unit, and 64 MB of RAM.
The HP LaserJet 4550N printer is the base model with a 6 GB hard drive, an HP JetDirect
610N print server (network card), a 500-sheet paper feeder, a duplex unit, and 64 MB of RAM.
12
C7085-90921 Chapter 1 Printer description 15
Figure 1-2 HP Color LaserJet 4550 series printers
1HP Color LaserJet 4550 and 4550N printers
2HP Color LaserJet 4550DN and 4550HDN printers
This printer series combines the quality and reliability of Hewlett-Packard printers with the features
listed in Table 1-1.
WWW For more information about printer features, refer to the Hewlett-Packard website at http://www.hp.com.
12
Table 1-1 Printer features
Feature Description
Connectivity Bidirectional parallel port (requires a “C” connector)
Two enhanced input/output (EIO) slots
Optional HP JetDirect 600N print server (network card)
(included with the HP Color LaserJet 4500 N and 4500 DN
printers)
Optional HP JetDirect 610N print server (network card)
(included with the HP Color LaserJet 4550N, 4550DN and
4550HDN printers)
HP Color LaserJet 4550 series: Infrared receiver port
HP Color LaserJet 4550 series: Embedded Web server
Duplex Optional duplex unit; mounts directly beneath the printer for
two-sided printing (duplex unit is standard with the HP Color
LaserJet 4500DN, 4550DN and 4550HDN)
Note Requires 40 MB of memory; 64 MB of memory
is recommended for optimal duplex printing.
If the 500-sheet paper feeder (Tray 3) is installed,
the duplex unit must be positioned between the
printer and Tray 3.
Environmental PowerSave setting
High content of recyclable components and materials
Fonts 80 internal fonts
16 Printer description C7085-90921
CPU The Color LaserJet 4500 series formatter PCB incorportates
a 133 MHz RISC processor
The Color LaserJet 4550 series formatter PCB incorporates a
233 MHz RISC processor
Memory—standard HP Color LaserJet 4500 series:
32 MB RAM (Base)
64 MB RAM (HP Color LaserJet 4500 N/4500 DN)
Memory Enhancement Technology (MEt), which automatically
compresses data to use RAM more efficiently
HP Color LaserJet 4550 series:
64 MB RAM (Base)
128 MB RAM (HP Color LaserJet 4550DN and HDN)
Memory Enhancement Technology (MEt), which automatically
compresses data to use RAM more efficiently
Memory—optional HP Color LaserJet 4500 series: Install 4, 8, 16, 32, or 64 MB
DIMMs into the three DIMM slots to a possible total 208 MB.
Synchronous SDRAM modules do not need to be configured
in pairs (in corresponding left and right slots). If you install
more than 208 MB of RAM, it will not be used by the printer.
HP Color LaserJet 4550 series: Install 64 or 128 MB DIMMS
into the two DIMM slots to a possible total of 192 MB. If you
install more than 192 MB of RAM, it will not be used by the
printer.
HP Color LaserJet 4550 series: 5 GB hard disk drive
(Included wit the HP Color LaserJet 4550HDN printer).
CAUTION: The HP Color LaserJet 4500 series uses 100-pin,
non-parity, SDRAM DIMMs. The HP Color LaserJet 4550
series uses 168-pin, non-parity, synchronous DRAM DIMMs.
Extended Data Output (EDO) DIMMs are not supported.
Table 1-1 Printer features (continued)
Feature Description
C7085-90921 Chapter 1 Printer description 17
Paper handling—input
tray capacity The capacities will vary depending on the media being used (for
example, transparencies, labels, heavy media, and envelopes).
Quantities based on 75 g/m2 (20 lb) media for both the HP Color
LaserJet 4500 and 4550 printers:
Tray 1: 150-sheet multipurpose tray
Tray 2: 250-sheet standard cassette
Tray 3: Optional 500-sheet paper feeder (included with the HP
Color LaserJet 4500DN, 4550DN and HDN models)
Paper handling—output
(face-down, correct-order
output)
Top output bin holds up to 250 sheets of standard paper.
Rear output bin holds up to 100 sheets of standard paper.
(The output of the rear output bin is in reverse order, facing
up.)
Printer-language support HP Color LaserJet 4500 series:
HP PCL5c
PostScript™ Emulation
Automatic language switching
HP Color LaserJet 4550 series:
HP PCL 5c
HP PCL 6
PostScript™ 3 Emulation
Automatic language switching
Paper sizes supported A4/Letter
Legal
Executive
JIS B5
A5
Custom (B5 ISO)
Print speed—
monochrome printing 16 pages per minute (ppm)
8 ppm for transparencies, heavy paper, and glossy paper
Print speed—
color printing 4 ppm
2 ppm for transparencies, heavy paper, and glossy paper
Standard interfaces The printer comes equipped with two EIO slots.
Note If the printer is not configured with a network
interface card, connect the printer using a
bidirectional parallel cable (IEEE-1284
compliant) with a “C” connector.
Table 1-1 Printer features (continued)
Feature Description
18 Printer description C7085-90921
Identification
Model and serial numbers
The model number and serial numbers are listed on identification labels located on the rear of the
printer. The model number is alphanumeric, such as C4084A for the HP Color LaserJet 4500. The
serial number contains information about the country of origin, the printer version, production code,
and the production number of the printer (see Figure 1-3). For information on determining the
version of printer you are servicing, see page 140.
Figure 1-3 Model and Serial number information
Note Two versions of the HP Color LaserJet 4500 series printers are available. Before servicing the printer
or ordering parts, you will need to identify which printer version you are servicing. For more
information, see page 140. The HP Color LaserJet 4550 series printer, unless otherwise specified,
is equivalent to the later version of the HP Color LaserJet 4500 series printer.
country
of origin
printer version
production numbe
r
production code
Table 1-2 Model names and numbers
Model Name Model Number
HP Color LaserJet 4500 C4084A
HP Color LaserJet 4500 N C4089A
HP Color LaserJet 4500 DN C4094A
HP Color LaserJet 4550 C7085A
HP Color LaserJet 4550N C7086A
HP Color LaserJet 4550DN C7087A
HP Color LaserJet 4550HDN C7088A
C7085-90921 Chapter 1 Printer description 19
Power and regulatory information
The identification labels on the rear of the printer also contain power rating and regulatory
information as shown in Figure 1-4.
CAUTION Converting the voltage on the printer can damage the printer. Do not use any voltage other than the
operating voltage. Any attempt to convert operating voltages will void the product warranty (for example,
attempting to change a 110V printer to a 220V printer).
Figure 1-4 Sample label
20 Printer description C7085-90921
Site requirements
The printer must be kept in a proper location to maintain the performance level that has been set at
the factory. In particular, be sure that the environment adheres to the specifications listed in this
chapter.
Below are recommendations for the printer location and placement.
Make sure the printer has the following:
a well-ventilated, dust-free area
a hard, level surface (not more than a 2° angle):
•for the HP Color LaserJet 4500 and 4500N, the surface must support 51 kg (112 lb)
•for the HP Color LaserJet 4500DN, the surface must support 77 kg (169 lb)
•for the HP Color LaserJet 4550 and 4550N, the surface must support 51 kg (112 lb)
•for the HP Color LaserJet 4550DN and 4550HDN, the surface must support 77 kg (169 lb)
a level surface that supports all four corners of the 500-sheet paper feeder
a constant temperature and humidity (Do not install near water sources, humidifiers, air
conditioners, refrigerators, or other major appliances)
Make sure to keep the printer:
away from direct sunlight, dust, open flames, or ammonia fumes.
away from the direct flow of exhaust from air ventilation systems.
away from walls or other objects. There must be enough space around the printer for proper
access and ventilation. See Figure 1-5 on page 21.
C7085-90921 Chapter 1 Printer description 21
Space requirements
The printer must have the following amounts of space above and around it.
Figure 1-5 Space requirements
1Top view
2Side view
22 Printer description C7085-90921
Electrical specifications
Table 1-3 lists the electrical specifications required to run the printer safely.
*When the printer is in standby (off) mode, it continues to consume a minimal amount of energy.
Note This information is preliminary and might not be current. Please see http://www.hp.com/support/
lj4550 for current information.
Environmental specifications
Keep the printer within the environmental conditions shown in Table 1-4 for optimum performance.
Table 1-3 Electrical specifications
Item 110-volt models 220-volt models
Power requirements 100-127 V (+/- 10%)
50/60 Hz (+/- 2 Hz) 220-240 V (+/- 10%)
50/60 Hz (+/- 2 Hz)
Power consumption
(typical)
During printing
During standby*
During PowerSave
Off
470 W (average)
80 W (average)
4500: 32 W
4550: 0 W
480 W (average)
90 W (average)
4500: 32W
4550: 0 W
Minimum recommended
circuit capacity for typical
product
4500: 16.0 A at 120 V
4550: 10.2 A at 120 V 4500: 7.1 A at 220 V
4550: 5.1 A at 220 V
Table 1-4 Environmental specifications
Item Operating
Temperature
Recommended
Allowed 20° to 26° C (68° to 79° F)
15° to 30° C (59° to 86° F)
Humidity
Recommended
Allowed 20% to 50% RH
10% to 80% RH
Altitude
Allowed 0 to 3100 m
(0 to 10,000 ft)
C7085-90921 Chapter 1 Printer description 23
Consumable storage requirements
The life of consumables is greatly affected by their storage environment. Use Table 1-5 to determine
the shelf life of stored consumables.
Printer specifications
Table 1-6 describes the dimensions of the printer.
Table 1-7 lists the acoustic emissions of the printer when it is printing and when it is in standby mode.
Table 1-5 Consumable storage requirements
Item Storage time Storage condition
Temperature Normal (maximum of
2.5 years) 0° to 35° C (32° to 95°
F)
Severe (maximum of
18 days) High 35° to 40° C (95°
to 104° F)
Low 0° to -20° C (32°
to -4° F)
Maximum temperature
change rate 40° to 15° C (104° to 59° F) within 3 minutes
-20° to 25° C (-4° to 77° F) within 3 minutes
Humidity Normal (maximum of
2.5 years) 35% to 85% RH
Severe (maximum of
18 days) High 85% to 95% RH
Low 10% to 35% RH
Atmospheric pressure 460 to 760 mm Hg (18.1 to 29.9 in Hg)
Average storage time 1 year
Table 1-6 Printer dimensions
HP Color LaserJet
4500, 4500N HP Color LaserJet
4500 DN HP Color LaserJet
4550, 4500N HP Color LaserJet
4550DN, 4550HDN
Height 395 mm (15.6 inches) 578 mm (22.8 inches) 395 mm (15.6 inches) 578 mm (22.8 inches)
Width 500 mm (19.7 inches) 500 mm (19.7 inches) 500 mm (19.7 inches) 500 mm (19.7 inches)
Depth 559 mm (22 inches) 709 mm (27.9 inches) 559 mm (22 inches) 709 mm (27.9 inches)
Weight 57 kg (125 lb) 75 kg (165 lb) 57 kg (125 lb) 75 kg (165 lb)
Table 1-7 Acoustic emissions
HP Color LaserJet 4500 Series HP Color LaserJet 4550 Series
Operating position
Printing
Standby
Per ISO 9296, DIN 45635, T.19
LPA 58 dB(A)
LPA 49 dB(A)
Per ISO 9296, DIN 45635, T.19
LPA 56 dB(A)
LPA 48 dB(A)
Bystander 1m
Printing
Standby
Per ISO 7779, DIN 45635, T.19
LPA 52 dB(A)
LPA 45 dB(A)
Per ISO 7779, DIN 45635, T.19
LPA 52 dB(A)
LPA 44 dB(A)
Sound power
Printing
Standby
Per ISO 9296
LWAd = 6.6 bels(A)
LWAd = 5.8 bels(A)
Per ISO 9296
LWAd = 6.7 bels(A)
LWAd = 5.3 bels(A)
24 Printer description C7085-90921
Note This product emits a sound intensity level, LWAd, at 6.4 bel during printing. Do not place the printer
in close proximity to users.
Maximum duty cycle is 35,000 pages per month.
C7085-90921 Chapter 1 Printer description 25
Printer assemblies
Figures 1-6 and 1-7 show the location of each major assembly in the printer. These assemblies are
described in Chapter 3.
Figure 1-6 Front view, HP Color LaserJet 4500 and HP Color LaserJet 4550
(shown with 500-sheet paper feeder and duplex unit)
1Top output bin
2Printer control panel
3Power switch (standby button)
4Duplex unit drawer (optional on 4500, 4500N, 4550 and 4550N models)
5Tray 3 (500-sheet tray; optional on 4500, 4500N, 4550 and 4550N models)
6Tray 2 (250-sheets standard tray)
7Intermediate Transfer Belt (ITB) drawer (transfer belt access)
8Tray 1 (150-sheet multipurpose tray)
9Drum drawer (imaging drum access)
10 Top cover release (toner access) button
11 Toner cartridge access cover
2
1
3
4
5
6
7
8
9
10
11
26 Printer description C7085-90921
Figure 1-7 Rear view, HP Color LaserJet 4500 (shown with 500-sheet paper feeder and duplex unit)
1Rear door (fuser access)
2Rear output bin door
3Cover for duplex unit
4Power receptacle for duplex unit
5Duplex unit power cord to the printer
6Printer power receptacle
7EIO slots
8Parallel connector (“C” connector)
9Memory access
1
2
3
4
6
7
89
5
C7085-90921 Chapter 1 Printer description 27
Figure 1-8 Rear view, HP Color LaserJet 4550 (shown with 500-sheet paper feeder and duplex unit)
1Rear door (fuser access)
2Rear output bin door
3Cover for duplex unit
4Power receptacle for duplex unit
5Duplex unit power cord to the printer
6Printer power receptacle
7EIO slots
8Parallel connector (“C” connector)
9Memory access
1
2
3
4
6
7
98
5
28 Printer description C7085-90921
Media requirements
Selecting print media
You can use many types of paper and other print media with this printer. This section provides
guidelines and specifications for selecting and using different print media.
Before purchasing any media or specialized forms in quantity, verify that your paper supplier
obtains and understands the print media requirements specified in the HP LaserJet Family Print
Media Guide. The guide is available through HP Direct. See the online user guide for ordering
information.
It is possible that media could meet all of the guidelines in this chapter and still not print
satisfactorily. This may be a result of abnormal characteristics of the printing environment or to
other variables over which Hewlett-Packard has no control (for example, extremes in temperature
and humidity).
Hewlett-Packard recommends testing any media before buying it in large quantities.
CAUTION Using media that does not conform to the specifications listed here and in the HP LaserJet Family
Print Media Guide can cause problems that require service. This service is not covered by the
Hewlett-Packard warranty or service agreements.
Media specifications
For optimum results, use conventional 75 g/m2 (20 lb) xerographic paper. Verify that the paper is of
good quality and is free of cuts, nicks, tears, spots, loose particles, dust, wrinkles, curls, or bent
edges. Avoid fanning the print media before loading it into the paper trays.
C7085-90921 Chapter 1 Printer description 29
Supported media weights and sizes
Table 1-8 shows the media types and sizes supported by the printer and the printer accessories.
Table 1-8 Supported media specifications
Tray Supported media Media
specifications Capacity
Tray 1 Paper
A4/Letter
Legal
Executive
JIS B5
A5
Custom
Minimum size:
76 by 127 mm (3 by 5 in)
Maximum size:
216 by 356 mm (8.5 by 14 in)
Single-sided:
If less than or equal
to 148 mm width:
60 to 176 g/m2
(16 to 47 lb)
If more than or equal
to 148 mm width:
60 to 135 g/m2
(16 to 36 lb bond)
Two-sided:
64 to 105 g/m2
(17 to 28 lb bond)
150 sheets of 75 g/m2
(20 lb) paper
Do not load more than the
maximum stack height of
15 mm (0.6 in)
Transparencies
A4/Letter
Glossy Paper
0.13 mm (5 mil)
120 g/m2
(32 lb/80 lb text)
Limit of 50
Limit of 50 sheets
Envelopes
(Tray 1 only)
Com10
Monarch
C5
DL
B5 (JIS)
Maximum weight:
90 g/m2 (24 lb
bond)
Limit of 10
Labels
(Tray 1 only) Limit of 50
Cardstock (postcards)
(Tray 1 only) Maximum weight:
176 g/m2 (47 lb
bond)
Maximum size:
200 mm by 148
mm
(7.87 in by 5.82 in)
Do not load more than the
maximum stack height of
15 mm (0.6 in)
Tray 2* Paper
A4/Letter
Legal
Executive
JIS B5
A5
Custom (B5 ISO)**
Single Sided
60 to 105 g/m2
(16 to 28 lb bond)
Two Sided:
64-105 g/m2 (17-
28 lb. bond)
250 sheets of 75 g/m2
(20 lb) paper
Transparencies
Glossy Paper 0.13 mm (5 mil)
120 g/m2
(32 lb/80 lb text)
Limit of 50 transparencies
Limit of 200 sheets glossy
30 Printer description C7085-90921
*Trays 2 and 3 do not support the range of custom sizes available in Tray 1.
**Trays 2 and 3 use custom size, specifically for B5 ISO.
Note Use only HP-supported transparencies (HP part number C2934A, Letter size; C2936A, A4 size).
Non-supported media
Use the following guidelines to avoid poor print quality or damage to your printer:
Do not use paper that is too rough.
Do not use paper that is embossed or coated unless it is specifically recommended for use in
this printer.
Do not use paper with cutouts or perforations other than standard three-hole punched paper.
Do not use multipart forms.
Do not use paper with irregularities such as tabs or staples.
Do not use letterhead paper with low temperature dyes or thermography. Preprinted forms or
letterhead must use inks that can tolerate temperatures of 190° C (374° F) for 0.1 second.
Do not use any media that produces hazardous emissions, or that melts, offsets, or discolors
when exposed to 190° C (374° F) for 0.1 second.
Do not use paper that has already been printed on or fed through a photocopier or printer.
Do not use paper with a watermark if you are printing solid patterns.
Do not duplex on glossy paper. Doing so will result in jams and print-quality problems.
Do not use transparencies that are not specified for use with HP Color LaserJet printers.
Tray 3*
(optional) Paper
A4/Letter
Legal
Executive
JIS B5
Custom (B5 ISO)**
Single Sided
60 to 105 g/m2
(16 to 28 lb bond)
Two Sided:
64-105 g/m2 (17-
28 lb. bond)
500 sheets of 75 g/m2
(20 lb) paper
Transparencies
Glossy Paper 0.13 mm (5 mil)
120 g/m2
(32 lb/80 lb text)
Limit of 50 transparencies
Limit of 500 sheets glossy
Duplex
printing
accessory
(optional)
Paper
A4/Letter
Legal
Executive
JIS B5
64 to 105 g/m2
(17 to 28 lb bond)
Table 1-8 Supported media specifications (continued)
Tray Supported media Media
specifications Capacity
C7085-90921 Chapter 1 Printer description 31
Printing on special media
Use these guidelines when printing on special types of media.
For optimum results, use conventional 75 g/m2 (20 lb) xerographic paper.
Verify that the paper is of good quality and free of cuts, nicks, tears, spots, loose particles, dust,
wrinkles, curls, or bent edges.
Transparencies
When printing on transparencies, use the following guidelines.
Do not send transparencies from Tray 2 to the rear output bin. The toner will be warm and may
cause the transparencies to stick together.
Send transparencies to the top output bin.
Handle transparencies using the edges. Oils from your fingers can remain on the transparency
and can cause print quality problems.
Use only overhead transparencies recommended for use in this printer. Table 1-9 describes the
recommended specifications for transparencies.
CAUTION Do not use DeskJet (inkjet) transparencies in this printer. The transparencies can become overheated
and melt, causing serious damage to your printer. Hewlett-Packard recommends using HP Color
LaserJet Transparencies with this printer. HP products are designed to work together for optimum
printing results.
Glossy paper
For optimum results when printing on glossy paper, select the glossy print setting in the printer driver.
You can also use the printer control panel to set the media type to GLOSS for the input tray you are
using. Because this setting affects all print jobs, it is important to return the printer to its original
settings once your job has printed. See the section in the online user guide on configuring input trays.
Note Do not duplex on glossy paper. Doing so will result in jams and print quality problems.
Colored paper
Colored paper should be of the same high quality as white xerographic paper. Pigments used must
be able to withstand the printer’s fusing temperature of 190° C (374° F) for 0.1 second without
deterioration. Do not use paper with a colored coating that was added after the paper was produced.
The printer creates colors by printing patterns of dots, overlaying and varying their spacing to
produce various colors. Varying the shade or color of your paper will affect the shades of your printed
colors.
Table 1-9 Printing on transparencies
Description Specifications
Electrical surface
resistivity 2.0 to 15 by 10 ohms per square inch
Fusing compatibility Materials must not discolor, melt, offset, or release
hazardous emissions when heated to 190°C
(374°F) for 0.1 second.
Caliper (thickness) 0.12 mm (0.0048 in) to 0.13 mm (0.0052 in)
32 Printer description C7085-90921
Heavy paper
Use Tray 1 for paper that is 105-157 g/m2 (28-42 lb bond). For optimum results when printing on
heavy paper, select the heavy print setting in the printer driver. You can also use the printer control
panel to set the media type to HEAVY for the input tray you are using. Because this setting affects all
print jobs, it is important to return the printer to its original settings once your job has printed.
CAUTION Do not use paper that is heavier than the recommended specification for this printer. Doing so can
cause misfeeds, jams, inferior print quality, and excessive mechanical wear. See Table 1-8 for
supported paper types and sizes.
Envelopes
Envelopes can only be printed from Tray 1. For information about loading envelopes, see the
section in the online user guide about loading envelopes into Tray 1.
Adhering to the following guidelines will help ensure proper printing of envelopes and help prevent
printer jams:
Do not load more than 10 envelopes into Tray 1.
The weight rating of envelopes should not exceed 90 g/m2 (24 lb).
Envelopes should be flat.
Envelopes must not be wrinkled, nicked, or otherwise damaged.
Envelopes with peel-off adhesive strips must use adhesives that can withstand the heat and
pressures of the printer’s fusing process.
Envelopes should be loaded with the flaps facing away from the printer and toward the left side
of the printer.
CAUTION To prevent severe printer damage, do not use envelopes that have windows, clasps, snaps, or
synthetic materials.
Labels
Note To print labels, Hewlett-Packard recommends configuring Tray 1 as a cassette and setting the tray’s
media type to LABELS in the printer control panel.
When printing labels, use the following guidelines:
Verify that the label’s adhesive material can tolerate temperatures of 190° C (374° F) for 0.1
second.
Verify that adhesive material is not exposed between the labels. Exposed areas can cause
labels to peel off during printing, which can cause printer jams. Exposed adhesive can also
cause damage to printer components.
Do not re-feed a sheet of labels.
Verify that labels lie flat.
Do not use labels that are wrinkled, bubbled, or otherwise damaged.
C7085-90921 Chapter 1 Printer description 33
Preprinted forms and letterhead
Observe the following guidelines for best results with preprinted forms and letterhead.
Forms and letterhead must be printed with heat-resistant inks that will not melt, vaporize, or
release hazardous emissions when subjected to the printer’s fusing temperature of
approximately 190°C (374°F) for 0.1 second.
Inks must be non-flammable and should not adversely affect any printer rollers.
Forms and letterhead should be sealed in a moisture-proof wrapping to prevent changes during
storage.
Before you load preprinted paper such as forms and letterhead, verify that the ink on the paper is
dry. During the fusing process, wet ink can come off of preprinted paper.
Recycled paper
This printer supports the use of recycled paper. Recycled paper must meet the same specifications
as standard paper; refer to the HP LaserJet Family Print Media Guide, available through HP Direct.
See the online user guide for ordering information. Hewlett-Packard recommends that recycled paper
contain no more than 5 percent groundwood.
34 Printer description C7085-90921
Environmental Product Stewardship Program
Protecting the environment
Hewlett-Packard Company is committed to providing quality products in an environmentally sound
manner. This HP LaserJet printer has been designed with several attributes to minimize impacts on
our environment.
This HP LaserJet printer design eliminates:
Ozone Emissions—This product has been designed to minimize ozone emissions and avoid
the need for an ozone filter.
CFC Usage—Class I U.S. Clean Air Act stratospheric ozone-depleting chemicals
(chlorofluorocarbons [CFCs], for example) have been eliminated from the manufacturing sites
that produce this printer. This practice coincides with the 1987 “Montreal Protocol on
Substances that Deplete the Ozone Layer” and its subsequent amendments. CFCs are not
used in manufacturing of the packing.
This HP LaserJet printer design reduces:
Energy Consumption—Energy usage drops significantly from printing mode to PowerSave
mode.
Paper Use—The printer’s optional duplex printing accessory provides two-sided printing,
reducing paper usage and the resulting demands on natural resources.
The design of this HP LaserJet printer facilitates the recycling of:
Plastics—Major plastic parts have markings that enhance the ability to identify plastics for
recycling purposes at the end of the printer’s life.
HP Toner Cartridges/Photoconductive Drum—In many countries, this product’s toner
cartridge/drum can be returned to HP at the end of its useful life. A prepaid shipping label and
instructions on how to return the toner cartridge/drum are included with the replacement toner
cartridge/drum. If your country is not listed in the replacement’s brochure, call your local HP
Sales and Service Office for further instructions.
HP recycling program information:
This HP LaserJet printer also contributes to protecting the environment in the following ways:
HP LaserJet printing supplies—In many countries, this product's printing supplies (e.g.,
toner cartridge, drum, fuser) can be returned to HP through the HP Planet Partners Printing
Supplies Environmental Program. An easy-to-use take-back component of the program is
available in over 25 countries.
Multilingual program information and instructions are included in every new HP LaserJet Toner
Cartridge and Consumables box.
HP Planet Partners printing supplies environmental program—Since 1990, the HP
LaserJet Toner Cartridge Recycling Program has collected more than 39 million used LaserJet
toner cartridges that otherwise might have been discarded in the world’s landfills. The HP
As an ENERGY STAR partner, Hewlett-
Packard Company has determined
that this product meets ENERGY STAR
Guidelines for energy efficiency.
C7085-90921 Chapter 1 Printer description 35
LaserJet toner cartridges go to a collection center and are bulk-shipped to our recycling partners
who disassemble the cartridge parts for recycling. Materials are separated and converted into
raw materials for use by other industries to make a variety of useful products.
U.S. Recycling Returns—For a more environmentally responsible return of used cartridges and
consumables, HP encourages the use of bulk returns. Simply bundle two or more cartridges
together and use a single, prepaid, and pre-addressed UPS label that is supplied in the package.
WWW For more information, call (800) 340-2445 (U.S. only) or visit the HP LaserJet Supplies website at http:/
/www.hp.com/ljsupplies/planet_index.html.
Non-U.S. Recycling Returns—Non-U.S. customers should call the local HP Sales and Service
Office for further information regarding availability of the HP Planet Partners LaserJet Toner
Cartridge and Consumables Recycling Program.
Paper—This printer is suited for the use of recycled papers (according to DIN 19 309) when the
paper meets the guidelines outlined in the HP LaserJet Family Print Media Guide.
For downloadable manuals, go to http://www.hp.com/support/lj4550. When you connect, select
Manuals. The user guide is provided on CD-ROM, which allows the same high-quality information to
be provided without consuming the large quantities of energy and natural resources required to
produce traditional paper manuals.
To ensure longevity of your HP LaserJet printer, HP provides the following:
Extended Warranty—HP SupportPack provides coverage for the HP hardware product and all
HP-supplied internal components. The hardware maintenance covers a three-year period from
date of the HP product purchase. HP SupportPack must be purchased by the customer within 90
days of the HP product purchase.
WWW Information on HP SupportPack is available on the Web at http://www.hp.com/ under the HP Services
and Support section. International customers can contact the nearest HP-authorized reseller about
this service.
Spare Parts and Consumables Availability—Spare parts and consumable supplies for this
product will be made available for at least five years after production has stopped.
36 Printer description C7085-90921
Regulatory statements
HP Color LaserJet 4500
For the most current regulatory statements regarding the HP Color LaserJet 4500 series, please
see the HP Color LaserJet 4500 User Guide, or go to http://www.hp.com/cposupport/prodhome/
hpcolorlas7857.html.
HP Color LaserJet 4550
For the most current regulatory statements regarding the HP Color LaserJet 4550 series, please
see the HP Color LaserJet 4550 User Guide, or go to http://www.hp.com/support/lj4550.
C7085-90921 Chapter 1 Printer description 37
Safety information
Laser safety statement
The Center for Devices and Radiological Health (CDRH) of the U.S. Food and Drug Administration
has implemented regulations for laser products manufactured since 1 August 1976. Compliance is
mandatory for products marketed in the United States. The printer is certified as a “Class 1” laser
product under the U.S. Department of Health and Human Services (DHHS) Radiation Performance
Standard according to the Radiation Control for Health and Safety Act of 1968. Since radiation
emitted inside the printer is completely confined within protective housings and external covers, the
laser beam cannot escape during any phase of normal user operation.
Material Safety Data Sheet
The Toner Cartridge/Drum Material Safety Data Sheet (MSDS) can be obtained by visiting the
website at http://www.ljsupplies.com/planetpartners/datasheets.html. International customers should
see support information in this guide for appropriate phone numbers and information.
Toner safety
Hewlett-Packard encourages responsible disposal of HP LaserJet printer consumable items through
its Environmental Collection Program. For details on this program, see the recycling instruction guide
enclosed with each consumable item.
Note In case of toner spills, skin and clothing are best cleaned by removing as much toner as possible with
a dry tissue, then washing with cold water. Hot water causes toner to permanently set into clothing.
38 Printer description C7085-90921
Laser statement for Finland
LASERTURVALLISUUS
Luokan 1 laserlaite
Klass 1 Laser Apparat
HP LaserJet 4500, 4550-laserkirjoitin on käyttäjän kannalta turvallinen luokan 1 laserlaite.
Normaalissa käytössä kirjoittimen suojakotelointi estää lasersäteen pääsyn laitteen ulkopuolelle.
Laitteen turvallisuusluokka on määritetty standardin EN 60825-1 (1994) mukaisesti.
VAROITUS !
Laitteen käyttäminen muulla kuin käyttöohjeessa mainitulla tavalla saattaa altistaa käyttäjän
turvallisuusluokan 1 ylittävälle näkymättömälle lasersäteilylle.
VARNING !
Om apparaten används på annat sätt än i bruksanvisning specificerats, kan användaren utsättas
för osynlig laserstrålning, som överskrider gränsen för laserklass 1.
HUOLTO
HP LaserJet 4500, 4550-kirjoittimen sisällä ei ole käyttäjän huollettavissa olevia kohteita. Laitteen
saa avata ja huoltaa ainoastaan sen huoltamiseen koulutettu henkilö. Tällaiseksi
huoltotoimenpiteeksi ei katsota väriainekasetin vaihtamista, paperiradan puhdistusta tai muita
käyttäjän käsikirjassa lueteltuja, käyttäjän tehtäväksi tarkoitettuja ylläpitotoimia, jotka voidaan
suorittaa ilman erikoistyökaluja.
VARO !
Mikäli kirjoittimen suojakotelo avataan, olet alttiina näkymättömälle lasersäteilylle laitteen ollessa
toiminnassa. Älä katso säteeseen.
VARNING !
Om laserprinterns skyddshölje öppnas då apparaten är i funktion, utsättas användaren för osynlig
laserstrålning. Betrakta ej strålen.
Tiedot laitteessa käytettävän laserdiodin säteilyominaisuuksista:
Aallonpituus 770-795 nm
Teho 5 mW
Luokan 3B laser
C7085-90921 Chapter 2 Service approach 39
2Service approach
Chapter contents
Service approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Parts and supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Ordering parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Ordering consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Exchange program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
World Wide Web . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
HP Service Parts Information Compact Disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
HP Support Assistant Compact Disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Ordering related documentation and software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Warranty statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Hewlett-Packard warranty statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Onsite service agreements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
40 Service approach C7085-90921
Service approach
Printer repair normally begins by using the printer’s internal diagnostics and the three-step process
below.
Step 1 Isolate the problem to the major system (for example, the host computer, the network
or server, or the printer system).
Step 2 Determine if the problem is located in the accessories or in the printer engine.
Step 3 Troubleshoot the problem using the procedures in Chapter 7.
Once a faulty part is located, the printer can usually be repaired at the assembly level by replacing
field replaceable units (FRUs). Some mechanical assemblies might need to be repaired at the
subassembly level. Hewlett-Packard does not support replacement of components on the printer
circuit assembles.
C7085-90921 Chapter 2 Service approach 41
Parts and supplies
Ordering parts
Field replaceable and accessory part numbers are found in Chapter 8 of this manual. Replacement
parts can be ordered from HP’s Commercial Support Services Organization-Americas (CSSO-A) or
HP’s Commercial Support Services Organization-Europe (CSSO-E).
Note Use only accessories specifically designed for this printer. Accessories can be ordered from an
authorized service or support provider. See “Ordering related documentation and software” on page
43 and “Ordering parts” on page 325 for additional ordering information.
By phone:
Commercial Support Services Organization-Americas (CSSO-A)
(1)(800) 227-8164 (U.S. only)
Commercial Support Services Organization-Europe (CSSO-E)
(49) (070) 3114-2253
By mail:
Ordering consumables
Consumables can be ordered directly from Hewlett-Packard. The phone numbers for ordering
consumables are:
U.S. (800) 538-8787
Canada (800) 387-3154; Toronto (416) 671-8383
United Kingdom 0734-441212
Other local phone numbers may also be available
Hewlett-Packard Company
CSSO-A
8050 Foothills Blvd.
Roseville, CA 95678
Hewlett-Packard Company
CSSO-E
Wolf-Hirth Straße 33
D-7030 Böblingen, Germany
42 Service approach C7085-90921
Exchange program
HP offers remanufactured assemblies for some parts. These are identified in Chapter 8 and can be
ordered through Commercial Support Services Organization-Americas (CSSO-A) or Commercial
Support Services Organization-Europe (CSSO-E).
Consumables
Paper and toner cartridges can be ordered directly from Hewlett-Packard. See Chapter 8 for
ordering information.
World Wide Web
Printer drivers, updated HP printer software, and product and support information can be obtained
from the following URL:
in the U.S.http://www.hp.com/go/support
Printer drivers may be obtained from the following sites:
In China:ftp://www.hp.com.cn/go/support
In Japan:ftp://www.jpn.hp.com/go/support
In Korea:http://www.hp.co.kr/go/support
In Taiwan:http://www.hp.com.tw/go/support
or the local driver website http://www.dds.com.tw
HP Service Parts Information Compact Disc
This powerful, CD-ROM-based parts information tool is designed to give users fast, easy access to
parts information such as pricing and recommended stocking lists for a wide range of HP products.
To subscribe to this quarterly service in the U.S. or Canada, call (800) 336-5987. In Asia Pacific,
call (65) 740-4484. Parts identification and pricing information can also be checked via the World
Wide Web at http://www.hp.com/go/partsinfo.
HP Support Assistant Compact Disc
This support tool offers a comprehensive online information system designed to provide technical
and product information about HP products. To subscribe to the quarterly service in the U.S. or
Canada, call (800) 457-1762. In Hong Kong, Indonesia, Malaysia, or Singapore, call Mentor Media
at (65) 740-4477.
C7085-90921 Chapter 2 Service approach 43
Ordering related documentation and software
Table 2-1 shows where to order related documentation and software. Telephone numbers for the
various sources are:
Commercial Support Services Organization-Americas (CSSO-A)
(800) 227-8164 (US only)
Commercial Support Services Organization-Europe (CSSO-E)
(49) (070) 3114-2253
HP Distribution Center (HPD) (661) 257-5565.
Fax: (805) 257-6995
Table 2-1 Related documentation and software
Description Part Number CSSO-A CSSO-E HPD
HP LaserJet Family Print
Media Guide 5963-7863 X
HP JetDirect Print Server
Administrator’s Guide 5969-6818 X X
Technical reference package 5021-0377 X
HP Color LaserJet 4500
Printer Drivers Disk C4084-60122
HP Color LaserJet 4500,
4500 N documentation bundle
(quick reference guide and
getting started guide)
C4084-99021 X
HP Color LaserJet 4500 DN
documentation bundle (quick
reference guide and getting
started guide)
C4094-99020 X
HP LaserJet 4550 Series
Getting Started Guide C7085-90901 X
HP Color LaserJet 4550/4500
Series Quick Reference
Service Guide
5963-7921 X
HP LaserJet 4550/4500
Series Service Manual C7085-90921 X X
HP Color LaserJet 4550/4500
Series Printer Service and
Support CD-ROM
C7085-60102 X X
HP Color LaserJet 4550
Series Printer Online User
Guide
C7085-60101
44 Service approach C7085-90921
Warranty statement
Hewlett-Packard warranty statement
HP Color LaserJet 4500,1 year limited warranty
4500 N, 4500 DN Printer and 4550/4550N/4550DN/4550HDN Printer
1HP warrants HP hardware, accessories and supplies against defects in materials and
workmanship for the period specified above. If HP receives notice of such defects during the
warranty period, HP will, at its option, either repair or replace products which prove to be
defective. Replacement products may be either new or like-new.
2HP warrants that HP software will not fail to execute its programming instructions, for the period
specified above, due to defects in material and workmanship when properly installed and used.
If HP receives notice of such defects during the warranty period, HP will replace software
media which does not execute its programming instructions due to such defects.
3HP does not warrant that the operation of HP products will be uninterrupted or error free. If HP
is unable, within a reasonable time, to repair or replace any product to a condition as
warranted, customer will be entitled to a refund of the purchase price upon prompt return of the
product.
4HP products may contain remanufactured parts equivalent to new in performance or may have
been subject to incidental use.
5The warranty period begins on the date of delivery or on the date of installation if installed by
HP. If customer schedules or delays HP installation more than 30 days after delivery, warranty
begins on the 31st day from delivery.
6Warranty does not apply to defects resulting from (a) improper or inadequate maintenance or
calibration, (b) software, interfacing, parts or supplies not supplied by HP, (c) unauthorized
modification or misuse, (d) operation outside of the published environmental specifications for
the product, or (e) improper site preparation or maintenance.
7TO THE EXTENT ALLOWED BY LOCAL LAW, THE ABOVE WARRANTIES ARE EXCLUSIVE
AND NO OTHER WARRANTY OR CONDITION, WHETHER WRITTEN OR ORAL, IS
EXPRESSED OR IMPLIED AND HP SPECIFICALLY DISCLAIMS THE IMPLIED
WARRANTIES OR CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, AND
FITNESS FOR A PARTICULAR PURPOSE.
8HP will be liable for damage to tangible property per incident up to the greater of $300,000 or
the actual amount paid for the product that is the subject of the claim, and for damages for
bodily injury or death, to the extent that all such damages are determined by a court of
competent jurisdiction to have been directly caused by a defective HP product.
9TO THE EXTENT ALLOWED BY LOCAL LAW, THE REMEDIES IN THIS WARRANTY
STATEMENT ARE CUSTOMER’S SOLE AND EXCLUSIVE REMEDIES. EXCEPT AS
INDICATED ABOVE, IN NO EVENT WILL HP OR ITS SUPPLIERS BE LIABLE FOR LOSS OF
DATA OR FOR DIRECT, SPECIAL, INCIDENTAL, CONSEQUENTIAL (INCLUDING LOST
PROFIT OR DATA), OR OTHER DAMAGE, WHETHER BASED IN CONTRACT, TORT, OR
OTHERWISE.
10 FOR CONSUMER TRANSACTIONS IN AUSTRALIA AND NEW ZEALAND: THE WARRANTY
TERMS CONTAINED IN THIS STATEMENT, EXCEPT TO THE EXTENT LAWFULLY
PERMITTED, DO NOT EXCLUDE, RESTRICT OR MODIFY AND ARE IN ADDITION TO THE
MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THIS PRODUCT TO
YOU.
C7085-90921 Chapter 2 Service approach 45
To ensure longevity of your HP LaserJet printer, HP provides the following:
Onsite service agreements
To provide you with the support level best suited to your system usage and support budget, HP has
onsite service agreements with three response times:
Priority Onsite Service is designed for production-critical applications, giving you four-hour service
response to your site for calls made during normal HP business hours.
Next Day Onsite Service provides onsite support by the next working day following your service
request. Extended coverage hours and extended travel beyond HP designated service zones are
available for additional charges on most on-site service agreements.
Weekly (Volume) Onsite Service Agreement, for organizations with many HP LaserJet printers,
provides economical, scheduled on-site coverage. Designated for customer sites using 25 or more
workstation products, this service provides scheduled weekly repair visits to your central location. HP
can write an agreement for any combination of 25 or more workstation products including printers,
plotters, computers, and disk drives.
For more information on HP service agreements, call (800) 835-4747 (U.S.) or (800) 268-1221
(Canada).
46 Service approach C7085-90921
C7085-90921 Chapter 3 Installation and configuration 47
3Installation and configuration
Chapter contents
Unpack the printer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Package contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Unpacking the printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Attaching the power cord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Installing the toner cartridges—for older version HP Color LaserJet 4500 printers . . . . . . . . 51
Installing the toner cartridges—for newer version HP Color LaserJet 4500 and HP Color
LaserJet 4550 printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Installing the imaging drum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Using the parallel cable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Selecting the display language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Testing the printer operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
Using PowerSave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Connecting to a network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Connecting to a LocalTalk network (J3111A only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Connecting to a 10Base2 network (J3111A only). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Connecting to a 10Base-T or 10/100Base-TX network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Enhanced I/O (EIO) configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
HP JetDirect print servers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
LocalTalk I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Printer drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Network configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Configuring the printer for the network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Configuring Novell NetWare frame type parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Configuration tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
NetWare 3.x and 4.x based products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Windows 3.1, Windows 95, and Windows NT 3.51 and 4.0 networks . . . . . . . . . . . . . . . . . . 71
IBM OS/2 LAN Server and Warp Server networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
LocalTalk network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
UNIX networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
Setting network security on the printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Locking the control panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Using an ASCII PJL escape sequence to set network security . . . . . . . . . . . . . . . . . . . . . . . 75
48 Installation and configuration C7085-90921
Unpack the printer
Figure 3-1 Package contents
Package contents
The following items are included with the printer:
1Printer guides: getting started guide (HP Color LaserJet 4500 and 4550) and quick reference
guide (HP Color LaserJet 4500 only)
2Software CD-ROMs (including printer drivers and software, network administrator utilities,
online user guide, and the HP JetDirect Print Server Installation Guide)
3Power cord
4Control panel overlay (for non-English language users)
5Parallel cable (only included with the HP Color LaserJet 4500 and 4550 base model printer)
6Imaging drum
7Four toner cartridges: cyan (C), magenta (M), yellow (Y), and black (K)
8Tray 3 (500-sheet paper feeder, included only with the HP Color LaserJet 4500DN, 4550DN
and 4550HDN printers)
9Duplex unit (included only with the HP Color LaserJet 4500DN, 4550DN and 4550HDN
printers)
12
3
4
5
6
7
8
9
C7085-90921 Chapter 3 Installation and configuration 49
Unpacking the printer
Note
Save all of the packing materials in case you need to repack and
transport the printer at a later date.
WARNING!
The base and N model printers weigh approximately 57 kg (125 lb). The
DN model weighs 77 kg (169 lb) with Tray 3 and the duplex unit
installed.
HP recommends having two or more people lift or move any of the
printers.
1Using safe lifting techniques, remove the printer and the printer
accessories from the box.
CAUTION
The prepared location must be level (not more than a 2° angle), able to
support up to 77 kg (169 lb), and must support all four corners of the
500-sheet paper feeder (serves as printer base).
2Place the 500-sheet feeder in the prepared location.
CAUTION
Avoid bending the guide pins while assembling the printer.
3Using the guide pins for proper alignment, carefully assemble the
printer and accessories.pen the ITB drawer and remove the packing
tape, then close the drawer.
4Open the ITB drawer and remove the packing tape, then close the
drawer.
1
3
2
4
50 Installation and configuration C7085-90921
Installation
Attaching the power cord
1Locate the standby button (power switch) on the front of the
printer.
2The standby button has two positions: in (power on) and out
(standby mode—the fans remain on). Make sure that the standby
button is out (standby mode).
3Locate the power cord on the back side of the printer for the HP
Color LaserJet 4500, 4500N, 4550 and 4550N printers or on the
duplex unit for the HP Color LaserJet 4500DN, 4550DN and
4550HDN printers. Connect the power cord to the power
receptacle on the back of the printer.
1
2
3
C7085-90921 Chapter 3 Installation and configuration 51
Installing the toner cartridges—for older
version HP Color LaserJet 4500 printers
Note
The following instructions are for older versions of the 4500 series
printers (see page 140 to determine which version of the printer you
have). See page 55 for instructions for installing toner cartridges in
newer version 4500 series and 4550 series printers.
1Locate the toner cartridges packaged in the printer box. The printer
uses four different toner colors and has a different toner cartridge
for each color: K = black, M = magenta, C = cyan,
and Y = yellow.
2Close all the doors and drawers on the printer. If the printer is not
already turned on, turn it on. Wait for the printer to warm up. When it
is ready, the control panel displays: TONER POSITION
CYAN = MISSING.
Note
If the INSTALL DRUM message appears, wait for the INSTALL TONER
CARTRIDGE message, then proceed with the following instructions.
3Push the dark gray release button on the side of the printer ([1]) and
open the top cover ([2]).
1
2
3
52 Installation and configuration C7085-90921
4The cartridge slot for the black toner cartridge is visible. Lift up the
flap that partially covers the cartridge slot. The correct toner color
is shown on the flap.
CAUTION
Do not shake the toner cartridges after removing them from the
packaging.
5Remove the cyan toner cartridge from the bag. Gently rotate the
toner cartridge from side to side to redistribute the toner.
6Remove the inside sealing tape by firmly pulling the orange tab
located on the end of the toner cartridge. (If the tab breaks off, pull
on the tape.)
CAUTION
Do not shake the toner cartridge after you have removed the inside
tape. Doing so could cause toner to spill.
7Position the toner cartridge over the cartridge slot so that the blue
arrow on the toner cartridge points to the blue arrow on the printer.
4
5
6
7
C7085-90921 Chapter 3 Installation and configuration 53
8Make sure that the tab on the other end of the toner cartridge aligns
with the notch on the cartridge slot.
Note
If the tab does not fit in the notch when you insert the toner cartridge,
the toner is the wrong color for that cartridge slot.
9Hold the toner cartridge so that the arrow on the right side of the
cartridge (the control panel side of the printer) points straight down.
10 Slide the toner cartridge down into the slot until the cartridge stops.
11 Rotate the toner cartridge toward the back of the printer (within the
cartridge slot) until the cartridge stops. The cartridge shutter opens
to reveal the developer sleeve.
9
8
10
11
54 Installation and configuration C7085-90921
12 Lower the flap to partially cover the toner cartridge and close the
top cover.
Note
You must close the top cover before installing the next toner cartridge.
13 On the printer control panel, press [VALUE +] once to prepare the
printer for installation of the next toner cartridge. When the printer
is ready, the control panel displays:
TONER POSITION
(color) = MISSING
14 Install the other three toner cartridges by repeating steps 3
through12. Install the cartridges in the following order:
1. black (K)
2. magenta (M)
3. cyan (C)
4. yellow (Y)
15 After installing the fourth toner cartridge, close the top cover and
press [GO]. Wait while the printer runs an internal color calibration.
The calibration takes a few minutes. When the printer is ready, the
control panel displays: READY.
CAUTION
If you need to ship the printer, remove the toner cartridges and
imaging drum before shipping.
12
13
14
15
C7085-90921 Chapter 3 Installation and configuration 55
Installing the toner cartridges—for newer
version HP Color LaserJet 4500 and HP Color
LaserJet 4550 printers
Note
The following instructions are for newer versions of the 4500 series and
4550 series printers (see page 140 to determine which version of the
printer you have). See page 51 for instructions for installing toner
cartridges in older version printers.
1Locate the toner cartridges packaged in the printer box. The printer
uses four different toner colors and has a different toner cartridge
for each color:
C = black; M = magenta; C = cyan; and Y = yellow.
2If the printer is not already turned on, turn it on and close all doors
and drawers. After the printer warms up for a few minutes, the
control panel displays: TONER POSITION
BLACK = MISSING.
3Push the dark gray release button on the left side of the printer ([1])
and open the printer’s top cover ([2]).
4The cartridge slot for the black toner cartridge is visible. Lift up the
flap that partially covers the cartridge slot.
5Remove the black toner cartridge from the bag and locate the
orange tab on the end of the toner cartridge. Pull the tab firmly to
remove the inside sealing tape. (If the tab breaks off, pull on the
tape.) Discard the tape.
6Position the toner cartridge over the cartridge slot so that the blue
arrow on the toner cartridge points to the blue arrow on the printer.
The arrow on the right (control panel side of the printer) should point
straight down.
1
2
3
4
6
5
56 Installation and configuration C7085-90921
7Slide the toner cartridge down into the slot until the cartridge
stops.
Note
If the cartridge does not slide easily into the slot, ensure that you have
the right color cartridge for that slot.
8Rotate the toner cartridge toward the back of the printer (within
the cartridge slot) until the cartridge clicks in place.
9Lower the flap to partially cover the toner cartridge. If the cartridge
was rotated correctly, the flap covers the cartridge label. Close the
top cover before installing the next toner cartridge.
10 When the top cover is shut, the carousel advances to the next
toner cartridge slot. When the printer is ready, the control panel
displays:
TONER POSITION
(COLOR> = MISSING
Install the other three toner cartridges by repeating steps 3
through 9.
11 After installing the fourth toner cartridge, close the top cover and
press [GO]. Wait while the printer runs an internal color calibration.
The calibration takes a few minutes. When the printer is ready, the
control panel displays: READY.
7
8
9
10
C7085-90921 Chapter 3 Installation and configuration 57
Installing the imaging drum
CAUTION
Avoid exposing the imaging drum to direct light. Exposure to light for
more than 15 seconds can seriously damage the imaging drum.
1Pull open the drum drawer until it stops.
2Align the imaging drum over the drawer so that the arrow on top
points to the rear of the printer, and the blue end cap on the side
slides into the slot identified with the blue arrow.
3Slide the imaging drum down into place.
4Push the front upper drawer shut. Wait while the printer runs an
internal color calibration. The calibration takes a few minutes. When
the printer is ready, the control panel displays READY.
CAUTION
If you need to ship the printer, remove the toner cartridges and imaging
drum before shipping.
10
9
1
2
3
4
58 Installation and configuration C7085-90921
Using the parallel cable
The printer can connect to the computer with a bidirectional parallel cable (IEEE-1284C compliant)
(see Figure 3-2). Connect the male “C” connector to the printer and the male “B” connector to the
computer. HP recommends that the parallel cable length be no longer than 10 meters (30 ft) in
length. The cable (HP part number C2946A) is included with the HP Color LaserJet 4500 printer
and the 4550 printer. It must be purchased separately for the HP Color LaserJet 4500N, 4500DN,
4550N, 4550DN and 4550HDN printers.
Figure 3-2 Parallel cable with a “C” connector
Parallel interface
When used to describe a parallel interface, the term bidirectional indicates that the printer is able to
both receive data from the computer and send data to the computer through the parallel port.
Note To use the enhanced capabilities of the bidirectional parallel interface such as bidirectional
communication between the computer and printer, faster transfer of data, and automatic configuration
of printer drivers, your software application must support these capabilities.
When you are using multiple ports, you can adjust automatic I/O switching to maximize
performance by using the timeout feature. If data from other ports appears in the middle of your
print job, increase the I/O timeout value.
C7085-90921 Chapter 3 Installation and configuration 59
Connecting a parallel cable
1Press the printer standby button (power switch) to place the printer
in standby mode. Turn off the computer.
2Plug the parallel cable into the printer’s parallel port until it snaps
into place.
3Plug the other end of the parallel cable into the computer. Tighten
the screws on the parallel cable to secure the cable to the computer.
4Turn the computer on and then turn the printer on.
Note
Your system will sense the printer (if your system is Plug and Play
compatible). Follow the directions on your screen. To install the
complete software package, cancel Plug and Play, and see the getting
started guide for more information.
3
4
2
1
60 Installation and configuration C7085-90921
Parallel cable pin configuration
To take advantage of the enhanced bidirectional parallel interface, use a 10-meter (30 ft.) parallel
cable (IEEE-1284 compliant) with a 25-pin DB male to a (IEEE-1284C) male “C” connector. Use
the following table to verify correct pin configuration.
Signal Name Printer Pin # Computer
Port #
nSTROBE 15 1
DATA 0 6 2
DATA 1 7 3
DATA 2 8 4
DATA 3 9 5
DATA 4 10 6
DATA 5 11 7
DATA 6 12 8
DATA 7 13 9
nACKNLG 3 10
BUSY 1 11
CALL (PE) 5 12
SELECT 2 13
NAutoFd 17 14
O VDC (GND) 19 – 35 18 – 25
nFAULT 4 15
nSe/In 16 17
nINIT 14 16
PERIPHLH 36
N.C. 18
C7085-90921 Chapter 3 Installation and configuration 61
Selecting the display language
To change the display language on the printer control panel, do the
following:
1Press and hold [SELECT] on the printer control panel while pressing
the standby button (power switch). Continue holding [SELECT] until
the control panel displays
SELECT LANGUAGE (in English), and then release the [SELECT] key.
2When the control panel displays LANGUAGE=ENGLISH *, press
[VALUE] repeatedly until your language choice appears.
3Press [SELECT] to save your language choice. An asterisk appears
next to the selected language. Then press [GO].
4After the printer warms up, the control panel displays READY in the
selected language. See Table 7-2 on page 217 if an error message
appears.
Note
If the control panel does not display the message in the language you
selected, press the printer standby button and repeat the instructions for
changing the display language.
1
2
3
4
62 Installation and configuration C7085-90921
Testing the printer operation
Print a configuration page to ensure that the printer is working
properly.
1On the control panel, press [MENU] until INFORMATION MENU
appears on the display.
2Press [ITEM] until
PRINT CONFIGURATION appears.
3Press [SELECT] to print a configuration page.
4After about 30 seconds, the configuration page prints. If it does
not print, see the “Troubleshooting flowchart” on page 213.
1
2
3
4
C7085-90921 Chapter 3 Installation and configuration 63
Using PowerSave
PowerSave reduces power consumption when the printer is not in use.
The factory default setting for PowerSave is ON, and the time setting is
one hour. The instructions below explain how to change the time setting
and how to turn PowerSave OFF.
1On the control panel, press [MENU] until CONFIGURATION MENU
appears on the control panel display.
2Press [ITEM] until
POWERSAVE=1 HR * appears on the HP Color LaserJet 4500, or
POWERSAVE=30 MIN * appears on the HP Color LaserJet 4550.
3Press [VALUE +] or [VALUE –] to display other time-setting choices
between 1 minute and 8 hours for the HP Color LaserJet 4500, or
turning PowerSave off. Time choices are between 1 minute and 4
hours for the HP Color LaserJet 4550; see the Resets Menu to turn
PowerSave off.
4Press [SELECT] to save your choice. An asterisk (*) appears beside
your saved choice.
5Press [GO]. The control panel displays READY.
1
2
3
4
5
64 Installation and configuration C7085-90921
Connecting to a network
The following ports are available on the HP JetDirect print servers:
1LocalTalk DIN-8 port (not available on the HP JetDirect J3113A
print server)
2BNC port for ThinLAN coaxial cable (not available on the HP
JetDirect J3113A print server
3RJ-45 port
Note
On the HP JetDirect J3113A print server, you can attach either a
ThinLAN cable or a 10Base-T cable, but not both at the same time.
See the instructions that follow to connect one or more network cables
to the printer.
Connecting to a LocalTalk network (J3111A
only)
Plug the end of your DIN-8 cable into the LocalTalk port on the HP
JetDirect print server. Attach the other end to the network.
Note
Network cables are not included with the printer. They must be
purchased separately.
Network cable connection
1
2
3
LocalTalk DIN-8 connection
C7085-90921 Chapter 3 Installation and configuration 65
Connecting to a 10Base2 network (J3111A
only)
1Attach one section of your ThinLAN cable to the BNC “T” connector.
2Attach another ThinLAN cable section ([1]) or a 50-ohm terminator
([2]) to the other side of the BNC “T” connector. If you are
attaching the printer to the end of your network, you must connect a
50-ohm terminator.)
Note
The BNC “T” connector and 50-ohm terminator for the 10Base-2
connection are not included with the printer. They must be purchased
separately.
3Connect the BNC “T” connector to the BNC port on the HP JetDirect
print server.
Note
The HP JetDirect J3111A print server supports one Ethernet cable
connection at a time.
BNC port
1
2
3
66 Installation and configuration C7085-90921
Connecting to a 10Base-T or 10/100Base-TX
network
Plug the connector of your unshielded twisted-pair cable into the
RJ-45 port. The other end of the cable should be attached to the
network.
Note
The HP JetDirect print server supports one Ethernet cable connection
at a time.
Plug the connector of your unshielded twisted-pair cable into the
RJ-45 port. The other end of the cable should be attached to the
network.
Note
The HP JetDirect Print server supports RJ-45 connection to 10Base-T
or 10/100Base-TX and Fast Infrared (FIR) and parallel ports.
HP Color LaserJet 4500 RJ-45 (10Base-
T or 10/100Base-TX) connection
HP Color LaserJet 4550 RJ-45 (10Base-
T or 10/100Base-TX) connection
C7085-90921 Chapter 3 Installation and configuration 67
Enhanced I/O (EIO) configuration
This printer comes equipped with two enhanced input/output (EIO) slots. These slots hold compatible
external devices such as the HP JetDirect 600N Print Server. Plugging EIO cards into the slots
increases the number of network interfaces available to the printer.
EIO cards can maximize printer performance when you are printing from a network. In addition, they
provide the ability to place the printer anywhere on a network. This eliminates the need to attach the
printer directly to a server or a workstation and enables you to place the printer closer to your
network users.
The printer control panel will have an additional menu (EIO Menu) if the printer is configured with EIO
cards. (See the chapter on using the printer control panel in the online user guide.)
Note Installation of cards and network configuration should be performed by a network administrator.
Note The HP Color LaserJet 4550 series printer supports the optional 5 GB hard disk drive (included with
the HP Color LaserJet 4550HDN printer). The HP Color LaserJet 4500 series printer does not support
an optional hard disk drive.
HP JetDirect print servers
HP JetDirect print servers (network cards) can be installed in one of the printer EIO slots. These
cards support multiple network protocols and operating systems. HP JetDirect print servers facilitate
network management by allowing you to connect a printer directly to your network at any location.
HP JetDirect print servers also support the Simple Network Management Protocol (SNMP), which
provides network managers with remote printer management and troubleshooting through HP
Web JetAdmin software.
68 Installation and configuration C7085-90921
LocalTalk I/O
The LocalTalk interface enables you to print directly from a stand-alone Apple Macintosh computer
or from a Macintosh computer on a LocalTalk network. For specific information about configuring
your computer and printer to print through a LocalTalk interface, refer to the printer’s getting started
guide and the HP JetDirect Print Server Software Installation Guide.
CPU
The HP Color LaserJet 4500 formatter PCB incorporates a 133-MHz RISC processor.
The HP Color LaserJet 4550 formatter PCB incorporates a 200-MHz RISC processor.
Fast InfraRed Receiver (optional)
The HP Fast InfraRed Receiver enables cableless printing from any IrDA-compliant portable device
(such as a laptop computer) to the HP Color LaserJet 4550 printer (when the optional FIR
accessory is installed).
The printing connection is maintained by positioning the sending FIR port within operating range.
Note that the connection can be blocked by objects such as a hand, paper, direct sunlight, or any
bright light shining into either the sending or receiving FIR port.
System requirements
In order to print with the HP Fast InfraRed Receiver, you will need:
the receiver connected to this printer
IrDA-compliant portable or other IR-capable host supporting IRLPT or JetSend
Communications Technology over IR
Microsoft Windows 9x, Windows NT 4.0, Windows 2000 or Mac 8.5 with a LaserWriter 8.6 or
higher driver
Note Older non-IrDA-compliant portable computers might not be compatible with the HP Fast InfraRed
Receiver. If you experience problems when attempting to print with the HP Fast InfraRed Receiver,
contact the manufacturer of or dealer for your portable computer to verify compatibility with the IrDA
standard.
For more information, see the HP Fast InfraRed Receiver User Guide that came with the HP Fast
InfraRed Receiver.
C7085-90921 Chapter 3 Installation and configuration 69
Printer drivers
The optimal way to control the printer is through settings in a software application or through the
printer driver. Changing print settings via a software application affects only that particular print job.
Most software applications allow you to choose print settings from menus within the application.
Software application settings and printer driver settings override the settings on the printer control
panel.
For best print quality, always select the paper or media type in the printer driver. Different media
types use different printer settings. For example, selecting transparencies in the driver causes the
printer to use a different color table, one designed for maximum print quality on transparencies.
Additionally, transparencies cause the printer to adjust printer speed and fuser temperature.
Other media types affect the printer settings as well: Selecting heavy or glossy media, for example,
causes the printer to change the engine speed.
The printer driver also gives you customized control of color text, graphics, and photos. The following
color control features are available only through your HP printer driver:
Halftone Options
HP ColorSmart II
Halftone options affect the resolution and clarity of your color output. You can select halftone settings
for text, graphics, and photos independently. The two halftone options are Smooth and Details.
HP ColorSmart II default settings will produce optimum results for most color printing needs.
However, you can also manually adjust color settings through the printer driver’s Vivid Color and
Screen Match color control options.
See the printer driver’s online Help for details on color settings and their effect on printed output.
70 Installation and configuration C7085-90921
Network configuration
Configuring the printer for the network
You can configure certain network parameters on the printer from the printer control panel or, for
most networks, from the HP JetAdmin Software (or the HP LaserJet Utility for Macintosh). The
utilities are provided on the printing software CD-ROM that comes with the printer. You can also set
these parameters from the HP Web JetAdmin Software, which is available at http://www.hp.com/go/
webjetadmin.
For a complete list of supported networks and for instructions on configuring network parameters
from software such as HP JetAdmin and HP Web JetAdmin, see the HP JetDirect Print Server
Software Installation Guide. The guide comes on the CD-ROM with printers in which an
HP JetDirect 600N print server is installed.
Note If you are configuring network parameters from the printer control panel, the control panel menu
appears in the languages listed below. If your language is not listed, the menu will appear in English
and you will need to configure the printer by using HP JetAdmin software (or the HP LaserJet Utility
for Macintosh).
DanishFrenchPortuguese
DutchGermanSpanish
EnglishItalianSwedish
FinnishNorwegian
Configuring Novell NetWare frame type parameters
The HP JetDirect 600N print server automatically selects a NetWare frame type. Select a frame
type manually only when the print server selects an incorrect frame type. To identify the frame type
chosen by the HP JetDirect 600N print server, print a configuration page.
C7085-90921 Chapter 3 Installation and configuration 71
Configuration tips
HP JetDirect 600N print servers (network cards) provide software solutions for:
Novell NetWare versions 3.x and 4.x
Microsoft Windows 3.1 and Windows 95
Microsoft Windows NT 3.51 and 4.0
IBM OS/2 LAN Server or Warp Server
LocalTalk
UNIX (HP-UX, Solaris, and SunOS)
For information about installing HP JetDirect 600N print servers and the types of interfaces and
network operating systems supported, see the HP JetDirect Print Server Software Installation Guide.
NetWare 3.x and 4.x based products
When using Novell NetWare 3.x and 4.x products with the HP JetDirect print server, queue server
mode provides improved printing performance over remote printer mode. For more information, see
the HP JetDirect Print Server Software Installation Guide.
Windows 3.1, Windows 95, and
Windows NT 3.51 and 4.0 networks
For Windows 3.1 and Windows 95 networks, HP JetAdmin software works as a Windows application
and supports native Novell Directory Services (NDS).
For peer-to-peer Windows 95 networks, HP JetAdmin software works as a Windows application, and
connects HP printers to an IPX/SPX-compatible printer network using an HP JetDirect print server.
For Windows NT 3.51 and 4.0 networks, HP JetAdmin software supports the TCP/IP or IPX/SPX
environments.
72 Installation and configuration C7085-90921
IBM OS/2 LAN Server and Warp Server networks
For IBM OS/2 LAN Server and Warp Server Networks, HP JetAdmin software supports the Data
Link Control (DLC) environment. Depending on the number of network printers and type of printer
driver, when using virtual memory, improved performance might be realized by increasing server
RAM, especially if the swapper.dat file is large.
LocalTalk network
The LocalTalk interface enables you to print directly from a stand-alone Apple Macintosh computer
or from a Macintosh computer on a LocalTalk network. For specific information about configuring
your computer and printer to print through a LocalTalk interface, refer to the printer’s getting started
guide and the HP JetDirect Print Server Software Installation Guide.
Macintosh DIN-8 cable
To connect a Macintosh computer directly to this printer, use a standard Macintosh DIN-8 printer
cable. This cable cannot be used in a network configuration.
Note For LocalTalk configuration, the DIN-8 printer cable must be plugged into the printer port of your
Macintosh computer.
LocalTalk configuration
To connect the printer to a Macintosh computer on a LocalTalk network, use the HP LocalTalk
Cable Kit. You will need a kit for each printer and an additional kit for each Macintosh computer on
your network.
UNIX networks
HP JetAdmin software provides a TCP/IP-based solution for configuring and managing HP
JetDirect print servers on HP-UX, Solaris, and SunOS systems.
C7085-90921 Chapter 3 Installation and configuration 73
Setting network security on the printer
This printer features control panel locking, which allows network administrators to prevent users from
changing certain printer control panel settings. When a menu is locked, unauthorized users trying to
change settings in the printer control panel will receive the following message:
ACCESS DENIED
MENUS LOCKED
You can use HP JetAdmin software, the HP LaserJet Utility for Macintosh, or an ASCII escape
sequence to perform this procedure. For instructions on locking the printer control panel using either
the HP JetAdmin software or the HP LaserJet Utility for Macintosh, see the online Help for these
utilities.
74 Installation and configuration C7085-90921
Locking the control panel
You can prevent users from changing printer control panel settings by establishing a password and
locking the printer control panel. The control panel offers multiple levels of security. You can lock
certain control panel menus, allowing users to change the rest of the menus, or you can lock all of
the menus—and you can even lock the [CANCEL JOB] key. When the printer control panel is locked,
unauthorized users who try to change settings at the control panel receive the following message:
ACCESS DENIED
MENUS LOCKED
Levels of security
Use HP JetAdmin software, HP LaserJet Utility for Macintosh, or an ASCII escape sequence to
perform this procedure. HP software, which comes on the software CD-ROM, is easier to use than
an ASCII escape sequence. For instructions about locking the control panel by using either HP
JetAdmin software or the HP LaserJet Utility for Macintosh, go to the online Help for that software.
Table 3-1 Printer security levels
Lock setting Control panel items locked
0 = None No items are locked
1 = Minimum Configuration Menu
I/O Menu Calibration Menu
Resets Menu
2 = Moderate Configuration Menu
I/O Menu
Calibration Menu
Resets Menu
Paper Handling Menu
3 = Maximum Configuration Menu
I/O Menu
Calibration Menu
Resets Menu
Paper Handling Menu
Information Menu
Printing Menu
[CANCEL JOB] key
C7085-90921 Chapter 3 Installation and configuration 75
Using an ASCII PJL escape sequence to
set network security
If you decide to use the ASCII escape sequence, you must use an MS-DOS® or Windows ASCII
editor to create the commands. The commands must also be sent to the printer by using a DOS
COPY command or an ASCII file download utility. The PJL Technical Reference Manual is located on
CD-ROM, part number 5961-0976. Order a copy of this manual from the HP website:
http://www.hp.com.
Note In the following examples, EC represents the escape character. For more information on using escape
characters, see the PJL Technical Reference Manual.
To lock or unlock the printer control panel if a password has not been set, send the following
ASCII sequence to the printer:
EC%-12345X@PJL JOB
@PJL DEFAULT CPLOCK=NONE
(or MINIMUM, MODERATE, or MAXIMUM)
@PJL EOJ
EC%-12345X
To set the password, send the following ASCII sequence to the printer:
EC%-12345X@PJL JOB
@PJL DEFAULT PASSWORD=[numeric password (0 to 65535)]
@PJL EOJ
EC%-12345X
To lock or unlock the control panel if the password has been set, send the following ASCII
sequence to the printer:
EC%-12345X@PJL JOB PASSWORD=(numeric password)
@PJL DEFAULT CPLOCK=NONE
(or MINIMUM, MODERATE, or MAXIMUM)
@PJL EOJ
EC%-12345X
76 Installation and configuration C7085-90921
C7085-90921 Chapter 4 Printer maintenance 77
4Printer maintenance
Chapter contents
Cleaning the printer and accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .78
Cleaning spilled toner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
Approximate replacement intervals for consumable items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Imaging drum life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Replacement intervals for consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Locating consumables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Replacing consumable items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Cleaning the toner density sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Replacing the toner cartridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Replacing the imaging drum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Replacing the transfer kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
Replacing the fuser kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Replacing the paper rollers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94
DIMM configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Adding memory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
78 Printer maintenance C7085-90921
Cleaning the printer and accessories
To maintain high print quality and performance, use the following opportunities to thoroughly clean
the printer and the paper handling accessories:
every time you change the toner cartridge (run a few pages through)
after printing approximately 5,000 pages for C (cyan), M (magenta), and Y (yellow); and 8,000
pages for K (black)
whenever print quality problems occur
Clean the outside surfaces with a water-dampened cloth. Observe the warning and caution below.
WARNING! Before you begin these steps, turn the printer off and unplug all power cords to avoid shock hazard.
Be careful when cleaning around the fusing assembly area. It might be hot.
CAUTION To avoid permanent damage to the toner cartridge, do not use ammonia-based cleaners on or around
the printer.
Do not touch the transfer roller. Skin oils on the roller can reduce print quality. If toner gets on your
clothes, wipe it off with a dry cloth and wash your clothes in cold water. Hot water sets toner into fabric.
Cleaning spilled toner
Defective toner cartridges can develop leaks. Also, after a paper jam has occurred, some toner
might remain on the rollers and guides inside the printer. The pages that print immediately after the
jam can pick up this toner.
CAUTION When cleaning the printer, do not touch the transfer roller with the damp cloth or with your fingers.
Vacuum specifications
Do not vacuum the printer or any spilled toner using a conventional vacuum. Toner particles used in
this product might be too fine for effective vacuuming and could result in damage to conventional
vacuums.
A vacuum specifically designed for cleaning toner can be used if it is capable of filtering fine
particles (5 microns in diameter).
Table 4-1 Cleaning the printer
Component Cleaning Method
Outside covers Use an HP Toner Cleaning Cloth (part number
5090-3379) or a water-dampened cloth. Do not use
solvents or ammonia-based cleaners.
Inside general With a dry lint-free cloth, wipe any dust, spilled
toner, and paper particles from the paper path area,
the registration roller, and the toner cartridge cavity.
Paper pickup, feed,
and separation rollers Use a water-dampened, lint-free cloth.
Separation pad Use a dry, lint-free cloth.
Registration roller Use a dry, lint-free cloth.
Transfer roller Use a dry, lint-free cloth. DO NOT TOUCH the
transfer roller with your fingers.
Fuser Use a water-dampened, lint-free cloth.
C7085-90921 Chapter 4 Printer maintenance 79
Toner catch tray and transport assembly
Thoroughly clean the toner catch tray, and clean or replace the paper transport assembly. These
assemblies are easily accessed once the fusing assembly has been removed (see “Toner catch tray
and paper transport assembly” on page 204).
To remove the toner catch tray, pull downward on the tab and slide the tray out of the rear of the
printer. To remove the transport assembly, remove the one screw (shown in Figure 6-69 on page
204) and then slide the assembly to the left. Once the assembly is free of the spline gear drive, you
can easily maneuver the assembly out of the rear of the printer. Thoroughly vacuum the assembly
and the cavity where the transport assembly rests.
When re-installing the transport assembly, there are two tabs on the right side of the assembly that
must be aligned to the printer’s frame; the white drive gear splines on the assembly must be aligned
with the driving gear mechanism on the printer.
80 Printer maintenance C7085-90921
Approximate replacement intervals for consumable items
Imaging drum life
Images versus pages
The life of the imaging drum (about 25,000 pages) is stated in terms of A-4/Letter-size images. The
number of images printed for each sheet of paper varies, depending on the mix of color, type of
format, and whether duplexing has occurred. The following guidelines will help determine drum life:
An “image” is a layer of toner. An A-4/Letter-size color page printed on one side contains four
A-4/Letter images, one for each color (CMYK).
A duplexed sheet counts as two pages. In color duplex mode (printing on both sides of a page),
there are eight A-4/Letter-size images per A-4/Letter sheet.
The page count numbers on the Configuration Page give a count of the number of pages
printed, regardless of size. For example, an A-4-size color duplexed page takes eight images to
print, but only adds two pages to the page count.
Usage patterns
How the printer is actually used can also have a significant effect on drum life:
Because of pre- and post-rotations, the drum wear is approximately the same for a one-page
job as for a two-page job. Frequent short jobs will decrease the drum life.
There are extra rotations and cleaning cycles when printing duplex pages. Duplex jobs use the
imaging drum at a higher rate than comparable simplex jobs.
“Drum life low” versus “drum life out”
The DRUM LIFE LOW warning message on the control panel indicates approximately 20 percent of
life remaining. This is intentional to allow the user enough time to order a replacement kit
(C4195A). It is perfectly acceptable to continue to print while the DRUM LIFE LOW message is
displayed. However, when the DRUM LIFE OUT message occurs, the drum has reached the end of
its life and the printer will not operate.
Key points to remember
The drum life specification assumes two-page jobs, one-sided printing on A-4/Letter-size
pages. When printing in color (four images per page), the number of pages will be 1/4 of the
images printed.
Due to the carousel arrangement of the color cartridges, color printing uses four images per
page even if only one color is actually used.
C7085-90921 Chapter 4 Printer maintenance 81
Drum life under different circumstances
The following graph shows the approximate life of the imaging drum for different types and sizes of
print jobs.
Figure 4-1 Imaging drum life
Note When printing black pages, there is a wider range of variation in pages/drum. The drum life will be well
below 25,000 images if only short monochrome jobs are printed.
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
1 2 5 10 15 20 2000
Pages/Drum (K)
Pages/job
A-4 simplex monochrome
A-4 duplex monochrome
A-4 simplex color
A4 duplex color
82 Printer maintenance C7085-90921
The following graph shows the drum life for printing in Letter and Legal formats:
Figure 4-2 OPC life
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
04812162024
4-color simplex Letter
4-color duplex Letter
Monocolor simplex Letter
Monocolor duplex Letter
4-color simplex Legal
4-color duplex Legal
Monocolor simplex Legal
Monocolor duplex legal
Engine, total page count
Pages/job
C7085-90921 Chapter 4 Printer maintenance 83
Replacement intervals for consumables
You can identify consumable items by their labeling and their blue plastic handles. For instructions on
installing consumables, see the installation guides supplied with each consumable item.
The following table lists the replacement intervals and part numbers for printer consumable items,
and the control panel messages that prompt you when it is time to replace each item.
CAUTION Hewlett-Packard recommends the use of HP products in this printer. Use of non-HP products can
cause problems the require service not covered by the Hewlett-Packard warranty or service
agreements.
Table 4-2 Approximate replacement interval for consumable items
Consumable Printer message Page count Approximate
time period1
1. Approximate lives are based on 2,000 pages per month.
Part number
Black (K) toner
cartridge
TONER K LOW or
TONER K OUT
9,000 pages 2
2. The approximate average A4/Letter-size page count is based on 5% coverage of individual toner
colors. Page counts are only estimations; usage conditions and print patterns cause results to vary.
4.5 months R94-4005-410CN
(see Table 8-1)
Cyan (C) toner
cartridge
TONER C LOW or
TONER C OUT
6,000 pages 23 months R94-4004-410CN
(see Table 8-1)
Magenta (M)
toner cartridge
TONER M LOW or
TONER M OUT
6,000 pages 23 months R94-4003-410CN
(see Table 8-1)
Yellow (Y) toner
cartridge
TONER Y LOW or
TONER Y OUT
6,000 pages 2 3 months R94-4002-410CN
(see Table 8-1)
Drum kit DRUM KIT OUT
REPLACE DRUM KIT
WASTE TONER FULL
REPLACE KIT
25,000 black-
and-white-
only pages, or
6,250 color
pages.
12.5 months for
black-and-white-
only pages, or 3
months for color
pages.
R94-4001-410CN
(see Table 8-1)
Transfer kit TRANSFER KIT OUT
REPLACE KIT
100,000
black-and-
white-only
pages, or
25,000 color
pages.
50 months for
black-and-white-
only pages, or
12.5 months for
color pages.
R96-5009-000CN
(see Table 8-1)
Fuser kit FUSER KIT OUT
REPLACE KIT
100,000
black-and-
white-only
pages, or
50,000 color
pages.
50 months for
black-and-white-
only pages, or
25 months for
color pages.
R96-5007-000CN
(110V)
R96-5008-000CN
(220V)
(see Table 8-1)
84 Printer maintenance C7085-90921
Locating consumables
Figure 4-3 illustrates the location of each consumable item.
Figure 4-3 Location of consumables
1Toner cartridges
2Imaging drum cartridge
3Intermediate transfer belt
4Transfer roller
5Air filters
6Fuser
7Paper feed and separation rollers
6
5
3
1
2
7
4
C7085-90921 Chapter 4 Printer maintenance 85
Replacing consumable items
Cleaning the toner density sensor
Clean the toner density sensor whenever the imaging drum is replaced
or when the control panel message displays: DENSITY SENSOR OUT OF
RANGE.
CAUTION
To avoid scratching the sensor, do not clean it with any paper products.
To clean the toner density sensor
1Open the ITB drawer and remove the cleaning brush mounted
inside.
2Open the drum drawer and remove the imaging drum using the blue
handle.
3Using the cleaning brush, remove all dust and toner particles from
the sensor as illustrated.
4Replace the imaging drum.
1
2
3
4
86 Printer maintenance C7085-90921
Replacing the toner cartridges
Replace the toner cartridge when the control panel displays:
TONER CMYK OUT.
The display can indicate that one or more toner colors are out.
1With the printer turned on and warmed up, push the dark gray
release button on the side of the printer ([1]) and open the
printer’s top cover ([2]).
Note
If you need to replace a toner cartridge and the TONER CMYK LOW or
TONER CMYK OUT messages are not displayed on the control panel,
open and close the top cover. Wait for the PRESS SELECT TO CHANGE
TONER message to appear on the control panel. Press [SELECT] and the
message TONER=(COLOR) appears on the printer control panel. Press
[–VALUE+] to select the toner cartridge you want to replace, and
proceed to the following steps.
2Lift the toner access cover and remove the used toner cartridge.
CAUTION
Do not shake the toner cartridges after removing them.
3Position the toner cartridge over the cartridge slot so that the blue
arrow on the toner cartridge points to the blue arrow on the printer.
The arrow on the right (control panel side of the printer) should
point straight down.
1
2
3
C7085-90921 Chapter 4 Printer maintenance 87
4Make sure that the tab on the other end of the toner cartridge aligns
with the notch on the cartridge slot.
Note
If the tab does not fit in the notch when you insert the toner cartridge,
the toner is the wrong color for that cartridge slot.
5Slide the toner cartridge down into the slot until the cartridge stops.
6Rotate the toner cartridge toward the back of the printer (within the
cartridge slot) until the cartridge stops. The cartridge shutter opens
to reveal the developer sleeve.
7Lower the toner access cover and close the printer’s top cover.
Note
You must close the top cover before installing another toner cartridge.
CAUTION
If you need to ship the printer, remove the toner cartridges and imaging
drum before shipping.
Note
If you receive a 54.2 error, see page 233 for more information.
4
5
6
7
88 Printer maintenance C7085-90921
Replacing the imaging drum
Replace the imaging drum when the printer control panel displays:
REPLACE DRUM KIT.
1Open the drum drawer and remove the used imaging drum.
2Locate the new imaging drum. Align it over the drawer so that the
arrow on top points to the rear of the printer, and the blue end cap
on the side fits into the slot identified with the blue arrow.
CAUTION
Avoid exposing the imaging drum to direct light. Exposure to light for
more than 15 seconds can seriously damage the imaging drum.
3Slide the imaging drum down into place and close the drawer.
CAUTION
If you need to ship the printer, remove the toner cartridges and
imaging drum before shipping.
1
2
3
C7085-90921 Chapter 4 Printer maintenance 89
Replacing the transfer kit
Replace the transfer kit when the printer control panel displays:
TRANSFER KIT OUT REPLACE KIT.
The transfer kit consists of an intermediate transfer belt (ITB), a transfer
roller, two air filters, and a hand wipe.
1Open the ITB drawer. Remove the used transfer belt by pulling up
on the green handles located on the sides.
2Locate the transfer roller inside the printer.
3To unlock the used transfer roller, gently push back and up (in a
rotating motion) on the blue triangles located on the lower corners
of the flap that is in front of the roller.
4Remove the used transfer roller by lifting it up and then out.
1
2
3
4
90 Printer maintenance C7085-90921
CAUTION
Avoid touching the foam portion of the roller. Oil from your fingers can
affect the print quality.
5Locate the new transfer roller and place it in the notches behind
the roller flap.
CAUTION
Be careful not to insert the transfer roller backwards. Doing so can
damage the printer.
6Snap the new transfer roller into place by pushing both ends of the
roller toward the rear of the printer.
7Remove the new transfer belt from the bag. Align the blue pins
that are on both sides of the new transfer belt with the blue slots in
the drawer. Then slide the transfer belt down into place. Close the
ITB drawer.
8To reset the printer for the new transfer kit, push [MENU] on the
control panel until RESETS MENU appears in the control panel
display.
5
6
7
8
C7085-90921 Chapter 4 Printer maintenance 91
9Press [ITEM] until TRANSFER KIT SELECT IF DONE appears in the
control panel display. Then press [SELECT].
10 To replace the air filters, turn the printer off and wait 10 minutes for
the fans to stop running. Unplug the power cord and open the upper
rear door of the printer. If the printer has a duplex unit, open the rear
cover of the duplex unit.
11 Remove the two used air filters from the rear of the printer. Then
use the hand wipe to clean excess dust away from the fan areas.
12 Insert the new air filters. Close all doors, plug in the printer, and turn
the printer on.
9
10
12
11
92 Printer maintenance C7085-90921
Replacing the fuser kit
Replace the fuser kit when the printer control panel displays:
FUSER LIFE OUT REPLACE KIT.
The fuser kit contains one fuser, four paper rollers, and a hand wipe.
WARNING!
To prevent possible burns, be sure the power cord is unplugged and
that the printer has cooled for 30 minutes.
1Open the upper-rear door of the duplex unit, if attached.
2Open the upper-rear door of the printer.
3Release the straps from the rear door by squeezing the latches on
the straps where the latches connect to the rear door.
4Inside the back of the printer, near the bottom, locate the two blue
latches on the fuser.
1
2
4
3
C7085-90921 Chapter 4 Printer maintenance 93
5Rotate the two blue latches upward 90 degrees.
6Grasp the finger holds on the fuser and pull the used fuser out of the
printer.
7Remove the new fuser from the bag using the finger holds. Holding
the new fuser by the finger holds, slide the fuser into the printer.
CAUTION
The blue latches will lock only if the fuser is installed.
8Lock the fuser in place by rotating the two blue latches down.
Reconnect the support straps to the upper rear door.
6
5
7
8
94 Printer maintenance C7085-90921
Replacing the paper rollers
1Remove Tray 2 from the front of the printer.
2On Tray 2, locate the paper roller and the cover next to the roller.
3Squeeze the cover release lever and open the cover.
4Remove the old paper roller from Tray 2 by squeezing together the
blue tabs and then sliding the roller off its spindle.
Note
The feed roller has a D-shaped hub and the separation roller has a
round-shaped hub.
1
2
3
4
C7085-90921 Chapter 4 Printer maintenance 95
5Install a new paper roller on Tray 2. Slide the new roller onto the
spindle until the roller clicks into place.
6Close the cover.
7Inside the tray cavity on the printer, locate the paper roller in the top
of the tray cavity.
8Squeeze the blue tabs on the roller and remove the old paper roller
from the tray cavity.
5
6
7
8
96 Printer maintenance C7085-90921
9Install a new paper roller on the tray cavity. Slide the new roller
onto the spindle until the roller clicks into place.
10 Replace Tray 2.
11 If you have the optional 500-sheet paper feeder (Tray 3), repeat
steps 3 through 9 to replace the two paper rollers for Tray 3.
12 Remove the paper roller in the tray cavity for Tray 3 in the opposite
direction from the paper roller in the other tray cavity.
9
10
12
11
C7085-90921 Chapter 4 Printer maintenance 97
13 Turn the printer on. When the printer control panel displays READY,
reset the printer for the new fuser kit and push [MENU] on the control
panel until RESET MENU appears.
14 Press [ITEM] until NEW FUSER KIT, SELECT IF DONE appears.
Then press [SELECT].
15 Press [GO] to return the printer to READY.
13
14
15
98 Printer maintenance C7085-90921
DIMM configuration
You can add additional Random Access Memory (RAM) to this printer by installing Dual Inline
Memory Modules (DIMMs). The HP Color LaserJet 4500 printer uses 100-pin, non-parity,
synchronous DRAM memory modules. The HP Color LaserJet 4550 printer uses 168-pin
synchronous DRAM memory modules. The SDRAM modules do not need to be configured in pairs
(in corresponding left and right slots).
Note Extended Data Output (EDO) DIMMs are not supported.
Adding memory
HP Color LaserJet 4500 printer
You can install 4, 8, 16, 32, or 64 MB DIMMs into the printer’s three DIMM slots. The DIMM slots
can be used to add memory, fonts, or firmware upgrades.
HP Color LaserJet 4550 printer
You can install 64 or 128 MB DIMMs into the printer’s two DIMM slots. The DIMM slots may be
used to add memory only. You can add fonts or firmware upgrades to the printer’s two 100-pin
slots.
Note The HP Color LaserJet 4500 printer will recognize RAM only up to 208 MB. The HP Color LaserJet
4550 printer will recognize RAM only up to 192 MB. Additional memory will not be used by either
printer.
To install memory in the printer, you must remove the formatter board from the rear of the printer.
To remove the formatter board, remove the six screws shown in Figure 4-4. The DIMMs are then
inserted into the available slots in the formatter board. See Appendix A in the online user guide for
installation instructions.
Figure 4-4 Removing the formatter board
CAUTION Do not attempt to remove the DIMM in slot #4 (see Figure 4-5) of the HP Color LaserJet 4500 printer,
or the DIMM in slot #3 (see Figure 4-6) of the HP Color LaserJet 4550 printer. This DIMM is part of
the printer’s firmware. Removing it will affect printer operation.
C7085-90921 Chapter 4 Printer maintenance 99
Figure 4-5 Do not remove the DIMM in slot #4.
Figure 4-6 Do not remove the DIMM in slot #3.
CAUTION The HP Color LaserJet 4500 printer uses 100-pin, non-parity, synchronous SDRAM DIMMs. The HP
Color LaserJet 4550 printer uses 168-pin, non-parity, synchronous DRAM DIMMs; EDO DIMMs are
not supported in either the HP Color LaserJet 4500 printer or the 4550 printer. To ensure you are using
the correct DIMM, see figure 4-7.
Figure 4-7 EDO and SDRAM memory modules
EDO SDRAM
100 Printer maintenance C7085-90921
Non-volatile memory (NVRAM)
The printer uses NVRAM to store I/O and information on the print environment’s configuration. The
contents of NVRAM are retained when the printer is deactivated or disconnected. There is one
NVRAM on the formatter and one on the DC controller.
C7085-90921 Chapter 5 Theory of operation 101
5Theory of operation
Chapter contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Basic operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
Image formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Primary charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
Laser exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Waste toner cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Fusing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Toner density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Mechanical system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112
Photosensitive drum cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Intermediate transfer belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Toner carousel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Laser/scanner operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Paper path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .122
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Tray 2 (cassette) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Tray 1 (multi-purpose tray) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Tray 3 (500-sheet paper feeder) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
Paper size detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .127
Fusing and delivery unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Duplex unit paper path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
DC controller subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Motors and fans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
Formatter system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
Control panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Power supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Power supply overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135
High-voltage power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
102 Theory of operation C7085-90921
Introduction
This section presents the theory of operation and the functional overview for HP Color LaserJet
4500 series and 4550 series printers. It provides the service representative with an understanding
of the printing process.
This chapter is also the course material for the Service Authorization class and discusses the
following printing functions:
Basic operation
Image formation
Toner density
Mechanical system
Paper path
DC controller subsystem
Motors and fans
Formatter system
Power supplies
Toner level sensing system
C7085-90921 Chapter 5 Theory of operation 103
Basic operation
HP LaserJet 4500 series and 4550 series printer functions are divided into three systems: the image
formation system, paper pick-up feed system, and engine control system. These systems are
thoroughly described in this chapter.
Figure 5-1 Basic system operation
Paper feeder (option)
LASER/SCANNER SYSTEM
Scanning mirror
Laser
diode
Scanner
motor
BD
circuit
IMAGE
FORMATION
SYSTEM
Photo-
sensitive drum Primary
charging roller
Cleaner unit
Developing
unit
Intermediate
transfer belt
Secondary transfer roller
ITB cleaning
roller
Cassette
Pick-
up
unit
Multi-purpose
tray
To external device (host computer, etc.)
through the video controller PCB
ENGINE
CONTROL SYSTEM
DC controller
PCB
Operation
panel
Cassette
PICK-UP/FEED SYSTEM
Face-up
tray Fixing
unit
Duplexing unit (option)
Face-down tray
Cassette paper
pick-up unit
Connector PCB
104 Theory of operation C7085-90921
Image formation
The image formation system is the central hub of the printer. During image formation, the color
image is created.
The image formation system consists of the following imaging units:
photosensitive drum cartridge
carousel, laser/scanner
toner cartridges
ITB unit
secondary transfer roller (see Figure 5-2)
A detailed description of the imaging units follows the image formation process.
Figure 5-2 Image formation
C7085-90921 Chapter 5 Theory of operation 105
Primary charge
The primary charge roller applies a negative DC bias to the drum. To maintain a consistent charge
across the drum’s surface, an AC bias is also applied. The charge voltage on the drum surface
ranges from approximately -700 V to -500 V. With the large negative charge on the drum surface, an
equal positive charge forms below the photoconductive material.
Figure 5-3 Primary charge
106 Theory of operation C7085-90921
Laser exposure
Photoconductive material, in the absence of light, allows the negative charge the charging roller
placed on the imaging drum’s surface to remain in place. Areas of the photoconductor that are
exposed to the laser become conductive and discharge the negative charge on the surface to the
metal cylinder of the drum. These discharged areas are what form the electrostatic image.
Figure 5-4 Laser exposure
Development
With the toner cartridge in position, a negative charge is applied to the toner particles. As the
developer sleeve and drum rotate past one another, the toner particles are drawn to the drum’s
surface. Areas of the drum’s surface that are exposed to the laser attract and hold the toner while
the unexposed areas repel the toner.
Figure 5-5 Development
C7085-90921 Chapter 5 Theory of operation 107
Transfer
During transfer, the toner image is transferred from the drum surface to the ITB (primary transfer) and
then from the ITB to the paper (secondary transfer).
Primary transfer
The ITB has a primary transfer roller that provides a positive bias that pulls the toner image from the
drum to the ITB. This process is repeated four times (one time for each toner cartridge). The positive
bias applied by the transfer roller increases with each pass to compensate for increasing layers of
toner. As shown in Figure 5-6, the toner particles still maintain their negative charge. Only the
transfer belt is charged positively.
Figure 5-6 Primary transfer
Secondary transfer
Once the entire print image is on the intermediate transfer belt, the secondary transfer roller is lifted
into position. At the appropriate time, a sheet of media is pulled into the transfer area. With the
secondary transfer roller biased at a positive potential, the toner on the ITB is pulled onto the media
as the ITB passes over the secondary transfer roller.
108 Theory of operation C7085-90921
Figure 5-7 Secondary transfer
Separation
As the media passes the secondary transfer roller, it passes over the charge eliminator. The charge
eliminator removes any positive charge on the media that came from the secondary transfer roller.
The elimination of positive charges decreases adhesion of the paper to the belt and allows for
better separation.
Figure 5-8 Separation
C7085-90921 Chapter 5 Theory of operation 109
Waste toner cleaning
The waste toner cleaning process begins when residual toner from the ITB is transferred to the
photosensitive drum. The toner is then transferred to the waste toner reservoir.
Waste toner cleaning operation
Although most of the toner is transferred from the ITB, some residual toner remains. The ITB
cleaning roller moves into position and places a positive charge on the residual toner. When the
residual toner reaches the drum, it is transferred to the drum’s surface by the drum’s negative
charge. The residual toner is then transferred from the ITB to the drum.
This waste toner is then removed from the drum’s surface by a cleaning blade, collected by the
sweeper strip, and placed in the waste toner reservoir by the waste toner transfer plates.
.
Figure 5-9 ITB residual toner cleaning
Figure 5-10 Waste toner to waste toner reservoir
110 Theory of operation C7085-90921
Fusing
The final step in the image formation process is the fusing of the toner to the media. The heat and
pressure provided by the fusing assembly serve two purposes: to permanently fuse the toner to the
media and to melt the toner together to produce the full-color image on the page. This process
uses upper and lower rollers made of Teflon tubing to reduce sticking. Both rollers are heated by
Halogen heaters, which cause the four colors to fuse and mix on the paper, creating the permanent
image.
Figure 5-11 Fuser
C7085-90921 Chapter 5 Theory of operation 111
Toner density
Maximum toner density is monitored and corrected if it is outside parameters to prevent variations in
the toner density. Toner density can vary as a result of environmental conditions, a deteriorated
photosensitive drum, or the amount of toner used.
A pattern of toner patches with varying densities is laid on the photosensitive drum. The DC
controller detects the density of these patches and determines the optimum developing bias for each
color. The DC controller uses the density sensor (PS14), located in the drum drawer assembly, to
read the density of the density detection pattern. PS14 contains a density detection circuit, a light-
emitting diode (LED), and photodiodes 1 and 2. To read the density, the sensor emits light from the
LED, reflects it off the density detection pattern on the photosensitive drum, and receives it with
photodiode 2. Photodiode 1 receives the light directly from the LED. The signals from photodiodes 1
and 2 are then compared to determine density values. Toner density is monitored and corrected
during the following occurrences:
when the power is activated
after a certain number of sheets are printed
when a toner cartridge is replaced
when the drum cartridge is replaced
when the printer wakes up after a standby mode of six hours or more
Figure 5-12 Toner density sensor
112 Theory of operation C7085-90921
Mechanical system
This section discusses each of the imaging units involved in the image formation process.
Photosensitive drum cartridge
The drum drawer assembly is a user-replaceable assembly that contains the photosensitive drum,
primary charging roller, drum memory, and waste toner storage. The drum motor (M4) drives the
drum drive assembly, which in turn drives both the photosensitive drum and the ITB (discussed
later in the mechanical system). Because the primary charging roller’s function was discussed in
the image formation section, only the drum memory and waste storage areas are covered here.
Photosensitive drum life
Located inside the drum cartridge is an EEPROM that stores an identification code along with drum
life and waste toner information. A life threshold value is used as a comparison number to indicate
when the drum has reached its end of life. During printer operation, the DC controller writes to the
drum memory at specific times: when power is deactivated, when the drum drawer is opened, or
whenever 20 pages are printed.
Figure 5-13 Photosensitive drum cartridge
Two messages appear as the drum cartridge reaches its end of life. The first is DRUM LIFE LOW,
which appears on the control panel when about 85 percent of the drum’s life has expired. When the
drum is 100 percent used, the message DRUM LIFE OUT appears and the printer stops printing. A
new drum cartridge must be installed at this time.
Waste toner
Inside the drum cartridge are three waste toner reservoirs that store the residual toner left behind
during image formation. As discussed earlier in the image formation section, the residual toner
from the ITB is transferred to the drum. A cleaning blade scrapes the residual toner off the drum’s
surface. The waste toner is then carried by toner feed plates into the waste toner reservoirs for
storage.
C7085-90921 Chapter 5 Theory of operation 113
Figure 5-14 Waste toner
As the waste toner reservoirs fill, a waste toner sensor (PS13) monitors the level of waste toner. Light
from a photo sensor emitter moves along a light guide to a window on the drum. The light passes
through one of the waste toner reservoirs, as shown in Figure 5-14, to the receiving side of the waste
toner sensor. A stirrer rotates past the window to clean away waste toner to prevent false readings.
As the reservoir fills, the length of time the window remains clear shortens. The DC Controller
monitors this time and when the threshold is reached the WASTE TONER FULL message is displayed
on the front panel. At this point, the printer stops printing and the drum cartridge must be replaced.
Under normal printing conditions the DRUM LIFE OUT message will be seen first. Only when printing
full-color pages with a high percentage of coverage or when a lot of waste toner is removed from the
ITB will the WASTE TONER FULL message be displayed before the DRUM LIFE OUT message.
Intermediate transfer belt
The entire print image forms on the intermediate transfer belt (ITB) before being transferred to the
media. The image formation section of this chapter includes a description of this process and
discusses operation of the motors and other items associated with the ITB. Figure 5-15 shows the
components associated with the ITB.
Figure 5-15 Transfer unit function
114 Theory of operation C7085-90921
When the printer receives a print command, the ITB is lifted into position against the drum. This is
accomplished when the ITB lift cam is rotated and the cams press against the lift levers located on
each side of the ITB. Drive force for the ITB lift cam is provided by M1 and applied to the cam when
CL2 is activated.
Once CL2 is activated to lift the ITB, both CL4 and CL3 are activated to position the transfer roller
and cleaning roller against the transfer belt. The transfer roller is used to stabilize the belt’s side-to-
side movement during its initial contact with the drum while the cleaning roller prepares the belt for
the image. Just before the black image reaches the transfer roller, both CL4 and CL3 are
deactivated again to remove the transfer roller and cleaning roller from the transfer belt. This
procedure only occurs when the ITB is lifted into position against the drum.
The print process continues as described in the image formation section. Once the full image is on
the ITB, both CL4 and CL3 are activated, and the transfer roller and cleaning roller are moved into
position against the ITB. This time the image is transferred from the ITB to the media. Any residual
toner left on the ITB is charged positively for removal.
Once the print job is complete, CL4 and CL3 are deactivated and the transfer and cleaning rollers
are moved away from the belt. CL2 is then deactivated and the ITB is lowered to move it away from
the drum.
Home position detection
The home position of the ITB is detected to precisely transfer the four toners to the intermediate
transfer belt and align the leading edge of print paper with the leading edge of the image.
In the area outside of the toner transfer area of the ITB, there are home position detection holes.
With the ITB rotating, the home position detection sensor (PS5) detects a hole and sends the
information to the DC controller.
When the ITB home position detection signal is detected by the DC controller, it sends a top-of-
page signal to the formatter. The formatter sends the image data and the DC controller begins to
create the image. For full-color printing, this process is repeated four times to form the image.
Figure 5-16 Home position detection
ITB unit life detection
The ITB counter unit is located on the side of the ITB unit. The counter unit consists of a number
gears, including the counter gear, and an ITB unit life detection lever. The gears indicate to the ITB
counter gear the number of rotations (turns) made by the intermediate transfer belt.
A “page count” is also stored on the formatter, which is used for informational purposes only. When
a configuration page is printed, the percentage of ITB life remaining is indicated based upon this
page count. If the ITB unit is replaced prematurely or the percentage of life is inaccurate, the page
count in the formatter must be manually corrected.
C7085-90921 Chapter 5 Theory of operation 115
Once the ITB counter gear has rotated one complete turn, the tabbed lever drops into the gear notch.
This causes the life detection lever to block light from the ITB unit life sensor (PS1). When light is
blocked from PS1, the DC controller sends the formatter a warning that the end of the ITB unit life
has been reached.
Figure 5-17 ITB unit life detection
Secondary transfer roller unit
The secondary transfer roller is normally detached from the ITB. This operation presses media
against the ITB with the secondary transfer roller at the time of secondary transfer. During “first page
out,” the secondary transfer roller engages with the belt prior to drum-to-belt image transfer to
stabilize the belt from side-to-side movement. The roller stays engaged while the black image is
being transferred to the ITB. Just before the black image reaches the secondary transfer roller, the
transfer roller disengages from the ITB.
Following image transfer from the photosensitive drum to the ITB and after the paper is positioned in
front of the registration rollers, the DC controller turns on the secondary transfer roller clutch (CL4).
Once CL4 is on, the secondary transfer roller contact/separation cam rotates and lifts the secondary
transfer roller mount. This presses the secondary transfer roller against the intermediate transfer belt
prior to the paper arriving from the registration rollers. Bias for the roller is turned on to enable image
transfer from the belt to the paper. Once the print job is finished and the paper has passed through
the unit, the DC controller then turns CL4 off and secondary transfer roller disengages from the ITB.
116 Theory of operation C7085-90921
Figure 5-18 Secondary transfer roller unit
ITB unit contact/separation unit
Normally, the intermediate transfer belt is separated from the photosensitive drum. This operation
presses the belt against the drum by moving the ITB unit contact lever at the beginning of print
operation.
When the fusing unit temperature reaches the print temperature at the beginning of the print
operation, the DC controller turns the ITB unit contact/separation clutch (CL2) on. Once the ITB
contact/separation clutch is on, the ITB unit contact/separation cam pushes on the ITB contact/
separation lever. This causes the lever to lift up on the ITB until it comes into contact with the
photosensitive drum. The ITB will stay engaged with the drum throughout the transfer process.
Once the entire print job is complete and CL3 and CL4 have been deactivated, the DC controller
turns CL2 off and the ITB is lowered away from the photosensitive drum.
C7085-90921 Chapter 5 Theory of operation 117
Figure 5-19 ITB unit contact/separation unit
118 Theory of operation C7085-90921
Toner carousel
The toner carousel holds the printer’s four toner cartridges: K (black), M (magenta), C (cyan), and
Y (yellow).
The carousel motor (M3) rotates the carousel, and the toner cartridge motor (M5) provides the
drive for the positioning cam and the developer sleeve.
The carousel contains three sensors: developing carousel position sensor (PS10), toner cartridge
contact/separation sensor (PS11), and the toner level sensor (PS12). These sensors, as well as
the detailed operation of the carousel assembly, are discussed on the following pages.
Figure 5-20 Toner carousel assembly
Operation
The DC controller activates the carousel motor (M3) and rotates the carousel. As the carousel
rotates, the position sensor (PS10) monitors the carousel for the stop position flags. Each stop
position flag is used as a development and toner cartridge removal flag (see Figure 5-21). When a
flag is detected, the DC controller monitors the time it takes the flag to pass the sensor (PS10).
Each flag is a different width and therefore takes various times to pass the sensor. This time lapse
is used by the DC controller to determine which development/removal stop position flag has
passed the sensor. When the carousel turns to the correct position, the DC controller stops the
carousel motor (M3) and the carousel from rotating any farther.
Table 5-1 Toner carousel assembly components
Reference Description
M5 Toner cartridge motor
M3 Carousel motor
PS10 Carousel position sensor
PS11 Toner cartridge contact/separation sensor
PS12 Toner level sensor
C7085-90921 Chapter 5 Theory of operation 119
Figure 5-21 Toner carousel operation
Toner cartridge contact/separation function
This function brings the developing sleeve closer to the photosensitive drum by pushing the toner
cartridge push cam out so that the toner cartridge rotates up onto the cam.
The DC controller determines the time lapse of the developing stop position flag with the carousel
position sensor (PS10) to determine that the toner cartridge is in position. The DC controller then
activates the toner cartridge motor (M5), and the motor begins to rotate clockwise. This causes the
toner cartridge push cam to rotate and push out. The toner cartridge then rotates up onto the cam.
This positions the toner cartridge and the developer sleeve near the drum and puts the spacers in
contact with the drum (see Figure 5-22).
The toner cartridge contact sensor (PS11) detects when the toner cartridge is close to the drum (see
Figure 5-22). Once the toner cartridge is facing the drum, the DC controller deactivates the carousel
motor (M3), which stops the rotation of the carousel. At the same time, the DC controller starts
development by rotating the toner cartridge motor (M5) counter clockwise to begin rotation of the
developing sleeve.
Once development is complete, M5 again rotates clockwise, moving the toner cartridge away from
the drum. The toner cartridge contact sensor detects when the toner cartridge has moved away from
the drum. The carousel motor (M3) again begins the carousel rotation, and the process is repeated
for each toner cartridge.
Figure 5-22 Toner cartridge contact/separation function
Toner level detection/toner cartridge detection
This function detects the remaining toner level in the toner cartridge and the presence of the toner
cartridge in the carousel.
120 Theory of operation C7085-90921
While the toner cartridge is facing the photosensitive drum, light from the light emitter diode passes
through the light guide in the carousel and enters the detection port of the toner cartridge. The light
passes through the cartridge when the toner around the detection port is scraped off by the
cartridge stirring function and is detected by the light receiver of the toner level sensor (PS12) (see
Figure 5-23). The printer measures the time it takes for the toner to cover the port again so that
light cannot pass through. This measurement determines the amount of toner remaining in the
toner cartridge.
When the light passing through the cartridge exceeds a specified time before being interrupted by
toner, the DC controller warns the formatter that the toner life is low. The TONER LIFE LOW
message also appears on the control panel. When light passes through the cartridge all the time
without interruption, the printer is stopped by the DC controller, and the formatter is notified that no
toner is left in the cartridge. A TONER OUT message also appears on the control panel.
Note The stirrer is also used to supply toner smoothly to the sleeve. The toner cartridge motor (M5) rotates
the stirrer and the toner feed roller. Both the stirrer and the toner feed roller stir the toner in the toner
cartridge.
Figure 5-23 Toner level detection/toner cartridge detection
Note The Color LaserJet 4550 series has a continuous toner level sensor (CTLS) that was not available
in the 4500 series. The continuous toner level sensing printed circuit assembly (PCA) is mounted on
the right side of the printer. The sensor allows the printer to track toner usage and to display toner
levels on the Supplies Status page.
Laser/scanner operation
The DC controller signals the laser driver to activate the laser diode that generates the laser beam.
The laser beam is aligned by the collimator lens and the cylindrical lens (see Figure 5-24). The
beam then strikes the six-faced prism mirror located atop the scanner motor, while the mirror is
rotating at a constant speed. The beam is then reflected and brought to a point to maintain a
consistent round dot (focused) on the drum surface by the focusing lens. At the beginning of the
scan line, the beam first strikes the beam detect (BD) mirror and then the BD PCB. After the initial
strike, the beam strikes the drum surface. With the drum rotating at a constant speed, the laser
beam successively scans across the drum’s surface, exposing the image.
C7085-90921 Chapter 5 Theory of operation 121
Figure 5-24 Laser/scanner operation
Photosensitive drum
BD PCB
BD mirror
Scanner motor
Laser driver
PCB Collimator lens
Cylindrical lens
Reflective mirror
Focusing lens
Six-faced prism mirror
Scanner driver
122 Theory of operation C7085-90921
Paper path
Introduction
For cassette feeding, a sheet of paper is picked up by the cassette pick-up roller and is then fed by
the feed rollers. For manual feeding, a sheet of paper is picked up by the multi-purpose tray pick-up
roller and is then fed by the feed rollers. The pick-up motor (M2) provides the drive for the front of
the paper path.
Once paper is fed into the general paper path, the paper passes through the registration rollers.
The paper is temporarily stopped so that the paper’s leading edge will match the leading edge of
the image on the photosensitive drum. The paper then passes between the secondary transfer
roller and the ITB. The paper continues past the web transport and past the upper and lower fusing
rollers to either the face-up tray or the face-down tray.
The paper path is shown in Figure 5-25.
Figure 5-25 Paper jam sensors (shown with the optional 500-sheet paper feeder and duplex unit installed)
1Registration paper sensor (PS2)
2Duplex paper-pick sensor (PS3104)
3Duplex unit pick-up paper sensor (PS3103)
4Reversed paper sensor (PS3101)
5Delivery paper sensor (PS7)
1
5
2
4
3
C7085-90921 Chapter 5 Theory of operation 123
Tray 2 (cassette)
The cassette paper sensor (PS8) senses paper in the cassette. Three paper-size detection switches
(SW801, SW802, and SW803) detect both the paper size and the presence of a cassette.
The timing of the paper pick-up and feeding is based on the home position of the ITB. The pick-up
motor (M2) provides the drive force for the front of the paper path. Once the paper-size detection
switch receives the ITB home position detection signal, the cassette feed solenoid (SL2) is activated
and transmits the rotational force of the pick-up motor to the cassette feeding pick-up roller. The roller
picks up the paper from the paper cassette.
A separation roller prevents multiple sheets from being fed while paper is fed into the printer’s paper
path. The cassette feed roller and another feed roller feeds the paper into the printer. The paper
passes the registration paper sensor (PS2) and reaches the registration roller. Because the
registration roller is not currently rotating, the paper temporarily stops. The paper’s leading edge is
then curled and any skew is corrected.
The DC controller activates the registration clutch (CL1), which feeds the paper to the secondary
transfer unit. The leading edge of the image on the intermediate transfer belt is matched with the
leading edge of the paper. The paper is fed to the fusing and delivery units (see Figure 5-26).
Figure 5-26 Tray 2 (cassette) operation
124 Theory of operation C7085-90921
Tray 1 (multi-purpose tray)
The multi-purpose tray paper sensor (PS4) senses the presence of the paper in the multi-purpose
tray. The manual feed solenoid (SL1) transmits the rotational force of the pick-up motor to the
manual feeding pick-up roller. As the pick-up roller rotates, the pick-up cam pushes up the paper-
lifting plate. This causes the paper to be pressed against the pick-up roller and thus picked-up by its
rotation. After the separation pad separates multiple sheets, the paper is fed into the printer one
sheet at a time.
Figure 5-27 Tray 1 manual feed
Table 5-2 Motors, solenoids, sensors, and switches
Reference Description
M2 Pick-up motor
SL2 Cassette pick-up solenoid
CL1 Registration clutch
PS2 Registration paper sensor
PS301 OHT sensor
PS8 Cassette paper sensor
SW801 Paper-size detection switch
SW802 Paper-size detection switch
SW803 Paper-size detection switch
Table 5-3 Motors, solenoids, clutches, and sensors
Reference Description
M2 Pick-up motor
SL1 Multi-purpose tray pick-up solenoid
CL1 Registration clutch
PS2 Registration paper sensor
PS3 Last paper sensor
PS4 Multi-purpose tray paper sensor
PS301 OHT sensor
C7085-90921 Chapter 5 Theory of operation 125
Last paper detected
The printer detects the last page of the print job before writing the next image. This prevents toner
particles from smearing on the photosensitive drum and ITB.
To detect the last paper, the last paper sensor (PS3) monitors the rotation of the last paper detection
roller on the multi-purpose tray. If there are two or more sheets in the multi-purpose tray, the last
paper detection roller does not rotate when one sheet is picked up. Once the last paper is picked up,
the last paper detection roller rotates. PS3 monitors this rotation, and a warning message is sent to
the control panel.
Figure 5-28 Laser paper detected
Overhead transparency detection
Overhead transparencies (OHT) are detected by the OHT sensor (PS301) located at the front of the
registration roller. Light is emitted from PS301 and passes through the paper path, reflected by the
reflective mirror, and returned to PS301. As paper passes over PS301, the light emitted from PS301
is blocked by the paper and thus does not return to PS301. Transparencies are detected when the
light passes through the OHT which is reflected by the prism, and returns to the sensor. The printer is
then switched to OHT mode and changes the paper path speed during transfer and fusing.
Figure 5-29 Overhead transparency sensor
126 Theory of operation C7085-90921
Tray 3 (500-sheet paper feeder)
Power supply
The printer supplies +24 V and +5 V to the paper feeder for power. The paper feeder is controlled
by the DC controller. It does not contain a microcomputer (CPU) or a drive motor. Its rollers are
controlled by the printer’s pick-up motor (M2).
Pick-up and feed system
Three switches (SW3001, SW3002, and SW3003) on the paper feeder PCB detect the paper size
and presence of a cassette. The DC controller activates the pick-up motor (M2) and turns on the
paper feeder pick-up solenoid (SL3001) after the pick-up motor starts. The paper feeder pick-up
roller is activated by the pick-up motor and picks up the paper. Once the separation roller separates
the paper from any extra sheets of paper, paper is fed into the printer by the paper feeder feed roller
and printer feed roller.
The rest of the paper path is the same as that in the Tray 2 cassette (see Figure 5-26).
Figure 5-30 Pick-up and feed system
Table 5-4 Solenoids, sensors, switches
Reference Description
SL3001 Paper feeder pick-up solenoid
PS3001 Paper feeder paper detection sensor
SW3001 Paper feeder paper-size detection switch
SW3002 Paper feeder paper-size detection switch
SW3003 Paper feeder paper-size detection switch
C7085-90921 Chapter 5 Theory of operation 127
Paper size detection
The paper size and the presence of the cassette are detected by the paper-size detection switches
(SW801, SW802, and SW803). The combinations of paper-size detection switches are listed in
Table 5-5.
Fusing and delivery unit
The fusing motor (M1) drives the fusing assembly, and the paper delivery rollers. Paper separated
from the ITB is fed into the fusing unit, and output from the fusing unit by the upper and lower fusing
rollers and fusing delivery roller. The paper output from the fusing unit is then detected by the
delivery unit paper sensor (PS7).
The pressure release sensor (PS6) detects when the fusing roller pressure is off.
The printer uses a deflector to switch between the face-up bin and face-down bin. When the face-up
bin is open, the paper is delivered to the face-up bin. When the face-up bin is closed, paper will be
delivered to the face-down bin (see Figure 5-31).
If the face-down bin becomes full, it is detected by the face-down bin paper full-sensor (PS9).
Figure 5-31 Fusing and delivery unit
Table 5-5 Paper size detection switches
Paper size Cassette paper-size detection switch
SW801 SW802 SW803
Legal OFF OFF ON
A4 ON ON ON
Letter OFF ON ON
Executive OFF ON OFF
B5 ON ON OFF
B5-ISO ON OFF OFF
A5 ON OFF ON
No cassette OFF OFF OFF
128 Theory of operation C7085-90921
Duplex unit paper path
Theory
The duplex unit enables printing on both sides of a page. With two-sided printing, known as
duplexing, the back side of the page is printed first. Then the page is sent through the duplex unit,
where it is flipped over and sent back through the printer for printing on the front.
Power supply
There are two power supplies for the duplexing unit: power supplied by the printer and power
supplied by the internal power supply. The CPU requires +5 V of power to be supplied from the
printer. This power is also used to supply power to the paper feeder. The external power supply
provides +24 V and +5 V, and is used to drive the motors, solenoids, and sensors.
Operation
Paper is fed into the duplexing unit by the duplex feed rollers, which are rotated by the duplex feed
motor (M3101). The paper is reversed by the reversing roller, which is rotated by the reversing
motor (M3102). The paper is then fed into the printer by the duplexing unit feed roller after the side
registration roller is adjusted by the side registration guide (see Figure 5-32).
Figure 5-32 Reversing and duplex pick-up operation
Table 5-6 Fusing and delivery unit components
Reference Description
M1 Fusing motor
PS6 Fusing unit pressure release sensor
PS7 Delivery unit paper sensor
PS9 Face-down bin full sensor
C7085-90921 Chapter 5 Theory of operation 129
Reversing operation
The media is guided to the duplex unit with the face-up deflector in conjunction with the face-up tray.
If the face-up tray is closed, the delivery deflector solenoid (SL3102) operates the deflector. The
duplex driver PCB turns the delivery deflector solenoid (SL3102). The rotation of the delivery
deflector solenoid moves the delivery deflector, feeding the media into the duplexer. The reversing
motor (M3102) rotates counter clockwise to feed the media into the reversing unit.
Once the reversed paper sensor (PS3101) detects the trailing edge of the paper fed into the reversed
unit, the duplex driver PCB changes the paper feed direction by rotating the reversing motor
clockwise. Paper is then fed along the lower duplex guide until the paper reaches the duplex feed
unit.
Figure 5-33 Reversing operation
Table 5-7 Motors, solenoids, and sensors
Reference Description
M3101 Duplex feed motor
M3102 Reversing motor
M3103 Side registration motor
SL3101 Duplex feed roller pressure release solenoid
SL3102 Delivery deflector solenoid
PS3101 Reversing unit paper sensor
PS3102 Face-up sensor
PS3103 Reversing unit stationary paper sensor
PS3104 Duplex pick-up paper sensor
PS3105 Side registration home position sensor
130 Theory of operation C7085-90921
Side registration adjustment
The printer adjusts side registration so that the center of the paper (in the horizontal direction),
matches the center of the printable area on the ITB when printing on the second side. The side
registration guides press against both sides of the paper in order to complete the adjustment.
The duplex driver PCB then drives the side registration motor (M3103) clockwise and moves the
home registration guide to the home position. Once the side registration home position sensor
(PS3105) detects the home position of the side registration guide, the duplex driver PCB stops
M3103 and holds the side registration guide at the home position.
Figure 5-34 Side registration adjustment
When the duplex paper pick-up sensor (PS3103) detects paper, the paper is fed along the feed
rollers.
Once the duplex paper pick-up sensor (PS3103) detects the paper, the paper is stopped and the
paper is freed from the feed rollers.
According to the paper-size data received from the DC controller, the duplex driver runs the side
registration motor (M3103) the prescribed number of pulses, moving the side registration guide and
aligning the paper position. This completes the side registration in the paper process.
Figure 5-35 Duplex feed roller pressure
C7085-90921 Chapter 5 Theory of operation 131
Duplex unit pick-up operation
After the side registration adjustment is completed, the duplex driver sends the refed paper presence
status to the printer. Once the status is reviewed by the printer, it sends the duplex unit pick-up
command to the duplex driver.
The duplex driver activates the duplex feed motor (M3101) and feeds the paper. When the paper is
detected by the registration paper sensor (PS2), the duplex driver deactivates M3101, stopping the
paper feed process. The duplex driver then activates M3101 to resume feeding once it receives the
refeed command. Once the media is in position, the duplex driver will deactivate M3101 and stop the
duplex feed roller. After the second side of paper is printed, the paper is fed to the face-down delivery
bin.
132 Theory of operation C7085-90921
DC controller subsystem
The DC controller is responsible for coordinating the entire printing process. The DC controller
enables the drive circuitry for the laser beam and coordinates print data from the formatter with
paper size, laser beam motion, the high voltage system, fuser temperature, and motors. The DC
controller also shares machine status information with the formatter so that proper diagnostic
messages appear on the control panel. An overview is shown in Figure 5-36.
Figure 5-36 DC controller PCB
C7085-90921 Chapter 5 Theory of operation 133
Motors and fans
The printer contains five motors that drive the paper pick-up/feed assembly and the image formation
assembly. The printer also contains three fans. Figure 5-37 and Table 5-8 illustrate the location of
each motor and fan.
Figure 5-37 Motors and fans
Fusing motor (M1)
The fusing motor is a two-phase stepping motor. This motor operates the fusing assembly secondary
transfer roller, feed belt, feed roller, ITB contact clutch, ITB cleaning roller contact clutch, and the
secondary transfer contact clutch.
Pickup motor (M2)
The pick-up motor is a two-phase stepping motor. The pick-up motor operates the cassette, multi-
purpose tray, paper feeder, and registration roller.
Carousel motor (M3)
The carousel motor is a two-phase stepping motor. The carousel motor operates the toner carousel.
M1 M2
FM2
FM1
M5
M4
M3
FM3
Table 5-8 Motor and fan locations
Reference Components
M1 Fusing motor
M2 Pick-up motor
M3 Carousel motor
M4 Drum motor
M5 Toner cartridge motor
FM1 Large fan
FM2 Small fan
FM3 Front fan
134 Theory of operation C7085-90921
Drum motor (M4)
The drum motor is a two-phase stepping motor. The drum motor operates the intermediate transfer
belt (ITB) and the photosensitive drum cartridge and its related components.
Toner cartridge motor (M5)
The toner cartridge motor is a two-phase stepping motor. The toner cartridge motor operates the
developer sleeve in the toner cartridge and performs the toner contact/separation function.
Fan motor
The fan motor is a DC brushless motor containing a hall element and the motor driver circuit. The
printer has two exhaust fans (FM1 and FM2) and one inducting fan (FM3).
C7085-90921 Chapter 5 Theory of operation 135
Formatter system
The formatter PCB is responsible for the following:
receiving and processing print data from the various printer interfaces
monitoring control panel inputs and relaying printer status information (through the control panel
and the bidirectional I/O)
developing and coordinating data placement and timing with the print engine
storing font information
communicating with the host computer through the bidirectional interface
controlling the PowerSave mode
The formatter PCB receives a print job from the bidirectional interface and separates it into image
information and instructions that control the printing process. The DC controller PCB synchronizes
the image formation system with the paper input and output systems, and then signals the formatter
to send the print image data.
The formatter PCB also provides the electrical interface and mounting locations for two EIO cards
and additional memory DIMMs.
CAUTION Never replace both the formatter PCB and the DC controller PCB at the same time. Doing so will result
in a complete loss of data. During the removal and replacement of the formatter, data is stored in the
DC controller. If the DC controller is also replaced before completing a power-on sequence, all data is
lost.
Control panel
The formatter PCB sends and receives printer status and command data via a control panel PCB. If
you replace the formatter PCB, updates will be sent to the DC controller PCB and vice-versa.
Power supplies
Power supply overview
There are three power supplies used to power various sections of the printer. There is an AC/DC
power supply and a high-voltage power supply. See Chapter 6 for instructions on accessing the
power supplies.
AC/DC power supply
The low-voltage power supply circuit supplies +24 VDC and +5 VDC required for the printer and +3.3
VDC and +5 VDC required for the video controller.
It also supplies +24 VDC for the paper pick up motor, scanner motor, and the high-voltage power
supply PCB, as well as +5 VDC for the sensors and the ICs on the DC controller PCB.
The front door switch or the rear door switch is deactivated by opening the drum drawer, ITB drawer,
toner access cover, or delivery door. These switches are in a series and disable the +24 VDC supply
when the drawers, covers, or doors are open.
The low-voltage power supply circuit monitors the 5 V signal fed back from the connector PCB to
ensure the 5 V power supply to the formatter.
136 Theory of operation C7085-90921
Overcurrent overvoltage protection
Each DC power supply circuit has an overcurrent protective function and overvoltage protective
function. This will prevent a power supply circuit failure by automatically interrupting the output
voltage when anomalies, such as a short circuit, develop on the loads that result in overcurrent flow
or abnormal voltage.
If this function is activated and no DC voltage is output from the low-voltage power supply circuit,
turn OFF the power switch (SW6), unplug the power cord, resolve the anomaly on the load, and
then turn ON the power switch (SW6) again.
Note Protective functions remain active for two minutes after activation. Wait for at least two minutes to
turn the power back on again.
High-voltage power supply
The printer contains two high-voltage PCBs mounted in one assembly. Together, these PCBs
generate the voltage supplied to the primary charging roller, developing sleeve, primary transfer
roller, secondary transfer roller, ITB cleaning roller, and upper fusing roller. DC voltage, or
superimposed AC voltage and DC voltage, is applied to the primary charging roller, developing
sleeve, and ITB cleaning roller. Positive or negative DC voltage is applied to the primary transfer
roller and secondary transfer roller. Negative DC voltage is applied to the upper fusing roller.
C7085-90921 Chapter 6 Removal and replacement 137
6Removal and replacement
Chapter contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Removal and replacement strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139
Repair notices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Caution regarding electrostatic discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Required tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
Types of screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Consumable assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Covers, drawers, and top and front assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Top cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Left side cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Right side cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Rear door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Right rear cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Drum drawer (top drawer) cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
ITB drawer (middle drawer) cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Control panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
Front right cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
ITB drawer (middle drawer). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
Radio Frequency Interference (RFI) shield. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Laser/scanner assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
DC controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Developing PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
Top cover switch assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
Drum drawer (top drawer) assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Densitometer assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Right side assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Formatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
Formatter PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Formatter pan assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Power supply. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
High-voltage power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Drum drive assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Large fan housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Carousel drive assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Paper size switch PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
Left side assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
Drawer switch assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
Paper feed PCB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183
Fusing motor (M1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185
Paper path pick-up motor (M2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
Paper pick solenoid (SL2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
ITB cleaning roller clutch (CL3). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
ITB clutch (CL2) assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
Transfer roller cam clutch (CL4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
Left side gears . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .193
138 Removal and replacement C7085-90921
Rear assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Large right side fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Left side fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Face-down assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
Internal assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Cartridge carousel assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Toner catch tray and paper transport assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Paper pick rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
C7085-90921 Chapter 6 Removal and replacement 139
Introduction
Removal and replacement strategy
This chapter explains how to remove and replace major printer components. (HP does not support
repairing individual subassemblies or troubleshooting to the component level.)
Replacement is generally the reverse of removal. Occasionally, directions for difficult or critical
replacement procedures are included.
WARNING! The information in this section is intended for authorized service personnel only.
Repair notices
WARNING! Turn the printer off, wait five seconds, then unplug the power cord before servicing the printer. Failure
to completely disconnect the printer could result in severe injury.
Never operate or service the printer with the protective cover removed from the scanner assembly.
The reflected beam, although invisible, can damage your eyes.
Never operate the printer with any parts removed.
The sheet-metal parts can have sharp edges. Be careful not to cut yourself when handling sheet-metal
parts.
CAUTION Always protect the imaging drum from light and physical contact when it is removed from the printer.
HP recommends reinstalling the original cover whenever the drum is removed from the printer.
Caution regarding electrostatic discharge (ESD)
The printer contains parts that are sensitive to electrostatic discharge (ESD). Watch for the ESD
reminder shown at the left when removing printer parts. Protect the parts that are sensitive to ESD
with protective ESD pouches.
140 Removal and replacement C7085-90921
Determining the printer version
Two versions of the HP Color LaserJet 4500 series printers are available. To accurately perform
removal and replacement procedures or determine the correct part for reordering, you will need to
know the version of the printer that is being serviced. To identify the printer, check the serial
number located at the rear of the printer. All printers will have US or JP in the first two positions of
the serial number (e.g., USBB123456). Newer versions of the HP Color LaserJet 4500 printers will
have an “H” or higher letter in the third position (e.g., USHB123456). If the letter in the third position
in the serial number is B, C, D, or F, then you have an older version. The HP Color Laserjet 4550
printer is equivalent to the newer version of the HP Color LaserJet 4500 printer, unless otherwise
specified.
Required tools
The following tools are needed to service the printer:
Phillips #2 magnetized screwdriver (152-mm [6-inch] shaft)
Small flat-blade screwdriver
Small needle-nose pliers
ESD strap
Penlight (optional)
All components in the HP Color LaserJet 4500 printer and the HP Color LaserJet 4550 printer use
Phillips-head screws that require a #2 Phillips screwdriver. Ensure that you have a Phillips
screwdriver and not a Posidriv screwdriver. Figure 6-1 (below) shows the difference between a
Phillips and a Posidriv screwdriver. Note that the Phillips tip has more beveled surfaces.
Figure 6-1 Phillips and Posidriv screwdriver comparison
PosidrivPhillips
C7085-90921 Chapter 6 Removal and replacement 141
Types of screws
Table 6-1 describes the screws used in the printer and provides guidelines to help determine where
each type of screw is used. The screws can vary in length depending on the thickness of the material
being fastened.
Always note where each type of screw is located and replace each one into its original location.
Table 6-1 Types of screws
Illustration Description Uses
Screw, machine w/washer To hold plastic to
metal.
example: printer skins
Screw, self tapping To hold plastic to
plastic.
example: control
panel
Screw, trus head To hold sheet metal to
sheet metal.
example: formatter
pan
Retaining ring (e-type) To hold a bolt through
a slot.
example: toner
catridge carousel
142 Removal and replacement C7085-90921
Consumable assemblies
The user replaces consumable assemblies as part of periodic maintenance. Chapter 4 explains the
maintenance procedures.
Note The printer tracks the amount of use on some of its user-replaceable parts by keeping a page count.
Swapping consumable assemblies between printers might cause a misrepresentation of consumable
assembly life values and is not recommended.
Table 6-2 Approximate replacement interval for consumable items
Consumable Printer message Page count Approximate time
period1
1. Approximate lives are based on 2,000 pages per month.
To install
Black (K) toner
cartridge
TONER K LOW or
TONER K OUT
9,000 pages 2
2. The approximate average A4/letter-size page count is based on 5 percent coverage of individual toner colors. Page
counts are only estimations; usage conditions and print patterns can cause results to vary.
4.5 months See page 86.
Cyan (C) toner
cartridge
TONER C LOW or
TONER C OUT
6,000 pages 23 months See page 86.
Magenta (M)
toner cartridge
TONER M LOW or
TONER M OUT
6,000 pages 23 months See page 86.
Yellow (Y) toner
cartridge
TONER Y LOW or
TONER Y OUT
6,000 pages 2 3 months See page 86.
Drum kit 4500:
DRUM KIT LOW or
DRUM KIT OUT
REPLACE DRUM KIT
4550:
DRUM KIT LOW
ORDER DRUM KIT
DRUM KIT OUT
REPLACE DRUM KIT
25,000 black
and white only
pages, or 6,250
color pages
12.5 months for black
and white only pages,
or 3 months for color
pages
See page 88.
Transfer kit 4500:
TRANSFER KIT LOW or
TRANSFER KIT OUT
REPLACE KIT
4550:
TRANSFER KIT LOW
ORDER TRANSFER KIT
TRANSFER KIT OUT
REPLACE KIT
100,000 black
and white only
pages, or
25,000 color
pages
50 months for black
and white only pages,
or 12.5 months for
color pages
See page 89.
Fuser kit 4500:
FUSER KIT LOW or
FUSER KIT OUT
REPLACE KIT
4550:
FUSER KIT LOW
ORDER FUSER KIT
FUSER KIT OUT
REPLACE KIT
100,000 black
and white only
pages, or
50,000 color
pages
50 months for black
and white only pages,
or 25 months for color
pages
See page 92.
C7085-90921 Chapter 6 Removal and replacement 143
CAUTION Hewlett-Packard recommends the use of HP products in this printer. Use of non-HP products can
cause problems that require service that is not covered by the Hewlett-Packard warranty or service
agreements.
144 Removal and replacement C7085-90921
Covers, drawers, and top and front assemblies
Top cover
To remove the top cover
1Open the drum drawer (top drawer) until it clears the top cover, and then remove the imaging
drum, protecting it from light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Push the release button on the left side of the printer and open the top cover.
3Open the rear door(s) of the printer.
4Remove the air filter.
5Remove the two screws from the top cover as shown in Figure 6-2.
6Lift up on the rear corners of the top cover to release the plastic retaining tabs from the side
cover.
7Rotate the back of the cover toward the left side of the printer, then lift to remove it.
Top cover replacement tip
When replacing the top cover, be sure to properly seat the two plastic retaining tabs on the
front of the cover.
Be sure to firmly seat the top cover.
Figure 6-2 Top cover removal and replacement (rear view of printer)
C7085-90921 Chapter 6 Removal and replacement 145
Left side cover
To remove the left side cover
1Open the drum drawer (top drawer) and remove the imaging drum, protecting it from light.
2Remove the top cover.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
3Open the ITB drawer (middle drawer) and Tray 2.
4Remove the two screws as shown in callout 1 of figure 6-3.
5Carefully pull out the bottom of the left cover, disengage the two tabs located behind the cover
(see callout 2 of figure 6-3), and then lift the cover up and off.
CAUTION Be careful to not break the tabs when pulling out the bottom of the cover.
Figure 6-3 Left side cover removal and replacement
1
2
146 Removal and replacement C7085-90921
Right side cover
To remove the right side cover from the printer
1Open the drum drawer (top drawer) and remove the imaging drum, protecting it from light.
2Remove the top cover.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
3Open the ITB drawer (middle drawer) and Tray 2.
4Remove the two screws shown in callout 1, Figure 6-4.
5Carefully pull out the bottom of the cover, and disengage the two tabs located behind the cover
(see callout 2, Figure 6-4) by sliding the cover to the rear. Lift the cover up and off.
Reinstallation tip
CAUTION When reinstalling the cover, ensure that the tabs on the inside of the cover (callout 2, Figure 6-4) are
seated properly by pushing in firmly on the tabs while sliding the cover forward into position.
Figure 6-4 Right side cover removal and replacement
1
2
C7085-90921 Chapter 6 Removal and replacement 147
Rear door
To remove the rear door
1Open the rear door of the printer.
2Push in the retaining strap connectors to release the two plastic retaining straps attached to the
inside of the rear door as shown in Figure 6-5.
3Slide the bottom of the rear door to your right until the plastic guide-pin clears the guide-pin
harness attached to the printer.
4Remove the rear door.
Figure 6-5 Rear door removal and replacement
148 Removal and replacement C7085-90921
Right rear cover
To remove the right rear cover
Note Remove the duplexer, if installed.
1Remove the top cover.
2Remove the right side cover.
3Remove the screw as shown in Figure 6-6.
4Rotate the top of the cover toward the left side of the printer and remove the cover.
Reinstallation tip
Ensure that the lip on the lower right side of the cover slides behind the lower rear cover.
Figure 6-6 Right rear cover removal and replacement
C7085-90921 Chapter 6 Removal and replacement 149
Drum drawer (top drawer) cover
To remove the drum drawer (top drawer) cover
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. To identify which printer
version you are servicing, see page 140. The HP Color LaserJet 4550 printer is equivalent to the newer
version of the HP Color LaserJet 4500 printer, unless otherwise specified.
1Open the drum drawer (top drawer) and remove the imaging drum, protecting it from light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Remove the two screws in the newer version HP Color LaserJet 4500 printer and HP Color
LaserJet 4550 printer (callout 1, Figure 6-7) or four screws in the older version HP Color
LaserJet 4500 printer (callout 2, Figure 6-7) from the inside of the drawer cover.
3Reach beneath the drum drawer (top drawer) cover, firmly grasping beneath the center of the
cover. Then, pull down slightly on the cover, rotating the bottom out toward you. Lift the cover up
to remove.
Figure 6-7 Drum drawer (top drawer) cover removal and replacement
2
1
150 Removal and replacement C7085-90921
Drum drawer (top drawer) cover replacement tip
When replacing the drum drawer (top drawer) cover, carefully insert the black plastic tabs into the
black plastic levers (Figure 6-8).
Note In newer version HP Color LaserJet 4500 and HP Color LaserJet 4550 printer, insert the metal tabs
(located just inside the black plastic tabs shown in Figure 6-8) into the drum drawer (top drawer)
cover before latching the cover onto the bottom of the drum drawer.
Figure 6-8 Drum drawer (top drawer) cover tabs and levers
C7085-90921 Chapter 6 Removal and replacement 151
ITB drawer (middle drawer) cover
To remove the ITB drawer (middle drawer) cover
1Open the ITB drawer (middle drawer) until it stops.
2Remove the two screws in the top of the ITB drawer (middle drawer) cover as shown in
Figure 6-9.
3Lift up on the cover slightly. Tilt the top toward you and then down to clear the two plastic
retaining tabs located in the lower middle of the cover and remove the cover.
ITB drawer (middle drawer) cover replacement tip
Secure the two plastic retaining tabs at the bottom of the cover prior to reassembling the ITB drawer
(middle drawer) cover.
Figure 6-9 ITB drawer (middle drawer) cover removal and replacement
152 Removal and replacement C7085-90921
ITB drawer (middle drawer)
To remove the ITB drawer (middle drawer)
1Pull the ITB drawer (middle drawer) completely out until it stops.
2Remove the intermediate transfer belt (ITB).
3Lift the drawer, clearing the first set of guide wheels from the guide rail (Figure 6-10). Pull the
guide rails until the next set of guide wheels stop, and then lift to clear the second set of guide
wheels from the guide rails.
Figure 6-10 ITB drawer (middle drawer) removal and replacement
C7085-90921 Chapter 6 Removal and replacement 153
Control panel
To remove the control panel
1Remove the top cover.
2Open the ITB drawer (middle drawer).
3Remove the black self-tapping screw as shown in Figure 6-11.
4Pull the bottom of the control panel out to clear the alignment pin.
5Lift the control panel up to access the cable.
6Disconnect the cable.
Figure 6-11 Control panel removal and replacement
154 Removal and replacement C7085-90921
Installing or changing the control panel overlay
You might need to install the control panel overlay or replace the English overlay with one that
displays your language. You also might need to configure the control panel to display messages in
your language.
1Locate the control panel overlay that came in the printer box and remove it from the bag.
If you are installing an overlay, rather than replacing one, skip to step 4. Otherwise continue to
step 2.
2Gently lift out on both sides of the overlay that is currently installed on the printer.
3Grasp the bottom of the overlay, pull it down, and then lift it out.
Note When removing the control panel overlay, you might want to use a small flat-blade screw driver to
gently pry off the control panel overlay.
4To install the new overlay, position it over the control panel and install the top side first. Insert
the top tabs on the overlay into the slots on the printer face. Then push the overlay up and push
in the bottom.
5Snap the overlay firmly onto the control panel.
45
C7085-90921 Chapter 6 Removal and replacement 155
Front right cover
To remove the front right cover
1Remove Tray 2.
2Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it from
light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
3Open the ITB drawer (middle drawer).
4Remove the control panel.
5Remove the three screws as shown in callout 1, Figure 6-12.
6Using a small flat-blade screwdriver, release the two plastic tabs (callout 2, Figure 6-12).
7Remove the cover.
Figure 6-12 Front right cover removal and replacement
2
1
156 Removal and replacement C7085-90921
Radio Frequency Interference (RFI) shield
To remove the RFI shield
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the 13 screws shown in Figure 6-13.
4Lift up on the RFI shield and remove.
Figure 6-13 RFI shield removal and replacement
C7085-90921 Chapter 6 Removal and replacement 157
Laser/scanner assembly
To remove the laser/scanner assembly
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the RFI shield.
4Disconnect the cable from the laser/scanner to the DC controller (J1006 on the DC controller).
See callout 1, Figure 7-37 on page 317.
5Free the cable harness from the two cable stays shown below in callout 1.
6Disconnect the flat ribbon cable and the other cable from the laser/scanner PCB.
7Remove the four long brass screws shown in callout 2.
8Tilt the narrow end of the laser/scanner assembly up, pull it toward you, and lift slightly to remove
it.
Figure 6-14 Laser/scanner assembly removal and replacement
1
2
158 Removal and replacement C7085-90921
DC controller
To remove the DC controller
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the RFI shield.
4Disconnect all connectors from the DC controller, including the two ribbon cables.
5Remove the five screws from the DC controller shown in Figure 6-15.
6Lift the DC controller up and out to remove.
DC controller replacement tip
The connectors are keyed and will fit in only one slot.
Figure 6-15 DC controller removal and replacement
C7085-90921 Chapter 6 Removal and replacement 159
Developing PCB
To remove the developing PCB
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the RFI shield.
4Remove the plastic shield (callout 1, Figure 6-16) by releasing the two tabs shown (callout 2,
Figure 6-16). If necessary, insert a flatblade screwdriver between the shield and the frame to
release the tab.
5Lift up on the shield to remove it.
Figure 6-16 Developing PCB removal and replacement (1 of 2)
6Disconnect the connectors from the developing PCB and release the cables from the metal cable
stay (callout 2, Figure 6-17 on page 160).
7Remove the five or four screws (depending on the version of printer that is being serviced) from
the developing PCB (callout 1, Figure 6-17 on page 160).
8Lift the developing PCB up and out.
Reinstallation tip
When securing the developing PCB with the five or four screws, secure the metal cable stay (callout
2, Figure 6-17) at the location shown.
1
2
160 Removal and replacement C7085-90921
Figure 6-17 Developing PCB removal and replacement (2 of 2)
1
2
C7085-90921 Chapter 6 Removal and replacement 161
Top cover switch assembly
Note Turn the printer off, wait five seconds, and then unplug the printer.
Two versions of the HP Color LaserJet 4500 series printers are available. To identify which printer
version you are servicing, see page 140.
To remove the top cover switch assembly
1Remove the top cover.
2Remove the left side cover.
3Remove the RFI shield.
4Disconnect the sensor and switch cables from the top cover switch assembly (callout 1, Figure
6-18 on page 162).
5Follow the instructions below, depending on the version of printer that is being serviced.
For HP Color LaserJet 4500 printer serial numbers xxG or lower:
1Free the sensor and switch cables from their cable stays.
2Remove the two screws from the top cover switch assembly (callout 2, Figure 6-18 on page 162).
3Slide the switch assembly to the left side of the printer, and then lift it up and out.
For printer HP Color LaserJet 4500 serial numbers xxH or higher and HP Color
LaserJet 4550 printers:
1Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it from
light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Free the cables from the five cable stays (callout 3, Figure 6-18 on page 162).
3Remove the two screws that secure the switch assembly and lower cable guide to the printer
frame (callout 1, Figure 6-19 on page 162).
4Pull the rear door switch arm toward the front of the printer while lifting the switch assembly up
and out slightly, taking care not to damage the cable guide.
5Release the five plastic retaining clips securing the switch assembly to the lower cable guide to
remove the switch assembly.
Replacement tip
When replacing the top cover switch assembly, make sure the cable is lying flat in the cable guide.
Secure the two tabs on the right side of the switch assembly/cable guide before snapping the three
tabs in place on the left side of the assembly.
162 Removal and replacement C7085-90921
Figure 6-18 Top cover switch assembly removal and replacement
Figure 6-19 Top cover switch assembly removal and replacement
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Drum drawer (top drawer) assembly
To remove the drum drawer (top drawer)
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it from
light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Remove the top cover.
3Remove the left side cover.
4Remove the RFI shield.
5For printer serial numbers xxG or lower, remove the top cover switch assembly.
6Disconnect connectors J1004 and J1010 on the DC controller (see callouts 2 and 3 in Figure
7-37 on page 317) and remove the cables from the cable stays.
7Disconnect the drum drawer (top drawer) switch (see callout 1, Figure 6-20).
Figure 6-20 Drum drawer (top drawer) switch
8Free the main cable from all cable stays at the top and left side of the printer; push the cables
back toward the rear of the printer.
9Remove the two screws from the black plastic housing shown in callout 1, Figure 6-21.
10 Lift the black plastic housing and slide it forward onto the front drawer.
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Figure 6-21 Drum drawer (top drawer) assembly removal and replacement
(1 of 3)
11 Slide a small flat-blade screwdriver under the black plastic retaining clips on the drawer guide
rails. Then lift the tab and pull the drawer out slightly to clear the latch that holds the plastic
retaining clips in place (see Figure 6-22 and Figure 6-23).
12 Pull the drum drawer (top drawer) straight out and away from the printer.
Reinstallation tip
When replacing the drum drawer (top drawer) assembly, make sure the cable is lying flat in the
cable guide.
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C7085-90921 Chapter 6 Removal and replacement 165
Figure 6-22 Drum drawer (top drawer) assembly removal and replacement
(2 of 3)
The following graphic shows an alternative method of removing the left side of the drum drawer.
Figure 6-23 Drum drawer assembly removal and replacement (3 of 3)
166 Removal and replacement C7085-90921
Densitometer assembly
To remove the densitometer
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it
from light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Remove the two screws on the densitometer as shown in callout 1, Figure 6-24, and move the
assembly slightly to the rear.
3Use a small, flat-blade screwdriver to release the tab shown in callout 2, Figure 6-24, and
remove the metal shield over the densitometer.
Figure 6-24 Densitometer removal and replacement (1 of 2)
4Remove the plastic cable cover as shown in Figure 6-25.
5Remove the cable from the cable stays, and then disconnect the connector from the
densitometer.
6Remove the densitometer by sliding it toward the rear of the printer.
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C7085-90921 Chapter 6 Removal and replacement 167
Figure 6-25 Densitometer removal and replacement (2 of 2)
168 Removal and replacement C7085-90921
Right side assemblies
Formatter
To remove the formatter
1Turn off the printer.
2When the fans are turned off, unplug the printer.
CAUTION Power is applied to the formatter as long as the printer is plugged in. Removing the formatter while
power is supplied to the printer can damage the formatter.
3Remove the six screws in the formatter shown in Figure 6-26.
4Slide the formatter out of the rear of the printer.
Figure 6-26 Formatter removal and replacement
Note The HP Color LaserJet 4550 printer formatter looks different externally, but the removal procedure
is the same as for the HP Color LaserJet 4500 printer.
C7085-90921 Chapter 6 Removal and replacement 169
Formatter PCB
To remove the formatter PCB from the cradle
Note Turn the printer off, wait five seconds, and then unplug the printer.
Before replacing the formatter or firmware, make sure to record the printer’s serial number, fuser
maintenance count, transfer maintenance count, color page count, and total page count.
1Remove the formatter from the printer by removing the six screws.
2Remove the EIO cards (if any) from the EIO slots.
3Disconnect the L-shaped (I/O) card from the formatter by lifting up on the narrow end of the PCB.
4While lifting the two black plastic tabs located over the EIO connectors on the formatter PCB,
slide the formatter PCB out of the cradle.
Note Lift the narrow end of the L-shaped (I/O) card so the connectors have clearance.
5Install the new formatter PCB by sliding it into the cradle.
6Reconnect the L-shaped (I/O) card to the formatter PCB.
7Pull all DIMMs from the old formatter PCB and install them on the new formatter PCB, making
sure the firmware DIMM is installed in the ROM ONLY DIMM slot of the HP Color LaserJet 4500
printer, or Slot #3 (J7) of the HP Color LaserJet 4550 printer.
8Install the EIO cards (if any).
9Install the formatter back into the printer.
10 Power up the printer in NVRAM initialization mode as follows:
Step 1 Hold down both the [CANCEL JOB] and [SELECT] keys until all the LED lights are on, then
release the keys.
Step 2 Press [CANCEL JOB].
Step 3 Press [SELECT].
11 Once initialization is complete, turn off the printer, then turn it back on in service mode (see
“Service mode” on page 293 for more information).
12 Enter the printer’s serial number, fuser maintenance count, transfer maintenance count, color
page count, and total page count.
13 Print a configuration page to verify printer operation.
170 Removal and replacement C7085-90921
Formatter pan assembly
To remove the formatter pan assembly
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Open the drum drawer (top drawer) until it stops and remove the imaging drum, protecting it
from light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Open the ITB drawer (middle drawer) and Tray 2.
3Remove the top cover.
4Remove the right side cover.
5Remove the right rear cover.
6Remove the left side cover.
7Remove the RFI shield.
8Remove the control panel.
9Remove the front right cover.
10 Remove the two screws for the connector cover shown in Figure 6-27.
Figure 6-27 Formatter pan assembly removal and replacement (1 of 4)
11 Disconnect the two connectors shown in callout 1, Figure 6-28.
C7085-90921 Chapter 6 Removal and replacement 171
Figure 6-28 Formatter pan assembly removal and replacement (2 of 4)
CAUTION A small, flat-blade screwdriver should be used to release the top connector by pressing on the latch.
Failure to use a flat-blade screwdriver to press on the latch will damage the connector.
12 Disconnect the ribbon cable from the DC controller shown in callout 1, Figure 6-29.
Figure 6-29 Formatter pan assembly removal and replacement (3 of 4)
Note Although Figure 6-29 depicts the RFI shield still installed, make sure this shield was removed at
step 7.
13 Remove the control panel cable from its cable stay, if necessary.
14 Remove the screws from the formatter pan assembly (shown in Figure 6-29 and Figure 6-30).
15 To remove the formatter pan, lift it slightly while pulling it out so that it clears the tabs.
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Figure 6-30 Formatter pan assembly removal and replacement (4 of 4)
Reinstallation tip
Be sure the four tabs (two on the top and one each on the rear and front of the formatter pan
assembly) are engaged prior to tightening the screws.
Be sure to reconnect the ribbon cable from the DC controller shown in callout 1, Figure 6-29.
C7085-90921 Chapter 6 Removal and replacement 173
Power supply
To remove the power supply
Note Turn the printer off, wait five seconds, and then unplug the printer.
Two versions of the HP Color LaserJet 4500 series printers are available; the later version is equivalent
to the HP Color LaserJet 4550 unless otherwise noted. To identify which printer version you are
servicing, see page 140.
1Remove the formatter pan assembly.
2Disconnect the four connectors (three in front and one in top rear of printer) from the power
supply.
3Free the cable harness from the cable stay.
4Remove the four or seven screws (depending on the version of printer you are working on) from
the power supply shown in Figure 6-31.
5Slide the power supply forward slightly to clear the rear retaining tab and tilt the top of the
assembly out. Lift the power supply up and out.
Figure 6-31 Power supply removal and replacement
174 Removal and replacement C7085-90921
High-voltage power supply
To remove the high-voltage power supply (HVPS)
Note Turn the printer off, wait five seconds, and then unplug the printer.
Two versions of the HP Color LaserJet 4500 series printers are available; the newer version is
equivalent to the HP Color LaserJet 4550 unless otherwise noted. To identify which printer version
you are servicing, see page 140.
1Remove the formatter pan assembly.
2Remove the power supply.
Note Some printers have a cover over the high-voltage power supply.
3Remove the rear door.
4Remove the fusing assembly.
5Disconnect the four cables from their connectors (callout 1, Figure 6-32 or callout 1,
Figure 6-33, depending on the version of printer being serviced).
6Free the cable harness from the cable stays.
7Remove the four brass screws shown in callout 2, Figure 6-32 from the HVPS.
8Carefully pull the HVPS out. Ensure that the rear plastic retaining strap attached to the HVPS
clears the chassis and its remaining components.
High-voltage power supply replacement tip
When reinstalling the HVPS, carefully insert the plastic retaining strap attached to the rear of the
HVPS through the chassis.
Figure 6-32 High-voltage power supply removal and replacement (newer version HP Color LaserJet 4500
and HP Color LaserJet 4550 printers)
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C7085-90921 Chapter 6 Removal and replacement 175
Figure 6-33 High-voltage power supply removal and replacement (older version HP Color LaserJet 4500
printers)
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176 Removal and replacement C7085-90921
Drum drive assembly
To remove the drum drive assembly
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Open both front drawers.
CAUTION Make sure the imaging drum is protected from light. Exposure to light for more than 15 seconds can
seriously damage the imaging drum.
2Remove the formatter pan assembly.
3Remove the power supply.
4Disconnect the two cables from the HVPS and free them from the cable stay.
5Remove the screw that secures the cable trough to the drum drive assembly as shown in
Figure 6-34.
Figure 6-34 Drum drive assembly removal and replacement (1 of 3)
6Carefully release the cable trough by pulling out slightly on the bottom and releasing the clip.
Depress the plastic v-shaped clip underneath the DC controller to loosen the cable guide. Slide
the trough toward the rear of the printer until it is free.
7Disconnect J204 on the developing PCB and free it from its cable stay.
8Remove the eight black screws from the drum drive assembly shown in Figures 6-35 and 6-36.
9Gently slide the drum drive assembly straight out from the printer assembly taking care not to
damage the cable.
C7085-90921 Chapter 6 Removal and replacement 177
Figure 6-35 Drum drive assembly removal and replacement (2 of 3)
Figure 6-36 Drum drive assembly removal and replacement (3 of 3)
178 Removal and replacement C7085-90921
Large fan housing
To remove the large fan housing
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the formatter pan assembly.
2Remove the four screws shown in Figures 6-37 and 6-38 (callout 1) from the large fan housing.
3Remove the large fan housing.
Figure 6-37 Large fan removal and replacement (1 of 2)
4Disconnect connector J209 on the developing PCB and free the cable from its cable stays.
5Unweave the cable from the cable trough to remove it.
6Remove the screw from the right rear fan housing shown in callout 2.
Figure 6-38 Large fan removal and replacement (2 of 2)
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C7085-90921 Chapter 6 Removal and replacement 179
Carousel drive assembly
To remove the carousel drive assembly
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the formatter pan assembly.
2Remove the rear door.
3Remove the large fan housing and the fan.
4Remove the toner level sensing assembly from the HP Color LaserJet 4550 (see Figure 6-39).
Figure 6-39 Toner level sensor assembly removal and replacement
5Free the cables from the rear cable trough located beneath the large fan housing shown in
callout 1.
6Disconnect the two motor cables from their connectors (J203 and J205) located on the
developing PCB and remove them from their trough.
7Disconnect the sensor as shown in callout 2.
8Disconnect the two high-voltage (red) cables from the HVPS and free the front cable from the
cable stays.
9Push up and out on the cable trough shown in callout 3 to release the lower tabs. Then tilt the
bottom of the cable trough out slightly to gain access to the top screws on the carousel drive
assembly.
Note To remove the cable trough, you might need to first loosen the screw on top of the developing PCB
housing.
180 Removal and replacement C7085-90921
Figure 6-40 Carousel drive assembly removal and replacement (1 of 2)
10 Remove the four screws shown in Figure 6-41 from the carousel drive assembly.
11 Carefully remove the carousel drive assembly by pulling the assembly straight out.
CAUTION Be sure to reconnect the sensor cables (see Figure 6-40, callout 2)
Carousel drive assembly replacement tip
When replacing the carousel drive assembly, be sure to align the “D” shaped shaft with the “D”
shaped hub located on the gear shown in the center of Figure 6-41.
Figure 6-41 Carousel drive assembly removal and replacement (2 of 2)
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Paper size switch PCB
To remove the paper size switch PCB
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Pull Tray 2 out.
2Remove the high-voltage power supply.
3Disconnect the connector as shown in callout 1.
4Remove the black screw from the paper size switch PCB shown in callout 2. Remove the switch
PCB.
Figure 6-42 Paper size switch removal and replacement
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182 Removal and replacement C7085-90921
Left side assemblies
Drawer switch assembly
To remove the drawer switch assembly
1Remove the top cover.
2Remove the left side cover.
3Disconnect the connector shown in callout 1.
4Remove the two screws from the drawer switch assembly shown in callout 2.
5Pull the drawer switch assembly away from the chassis.
Replacement tip
Open both front drawers for easier installation.
Figure 6-43 Switch plate assembly removal and replacement
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Paper feed PCB
To remove the paper feed PCB
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the rear door.
4Remove the fusing assembly.
5Disconnect the small fan connector shown in callout 1.
Figure 6-44 Paper feed PCB removal and replacement (1 of 3)
6Remove the three screws from the left rear sheet metal fan shield shown in Figure 6-44 and
Figure 6-45 (callout 2) and remove the shield.
Figure 6-45 Paper feed PCB removal and replacement (2 of 3)
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184 Removal and replacement C7085-90921
7Remove the screw in the black plastic cover shown in callout 3, Figure 6-44.
8Remove the black plastic cover.
9Remove the eight cables from their connectors on the paper feed PCB shown in Figure 6-46.
10 Remove the screw from the rear of the paper feed PCB (callout 4, Figure 6-46).
11 Carefully remove the paper feed PCB by sliding the board backwards, then tilt the top of the
board forward to clear the top of the board from the metal tab along the top of the PCB.
Paper feed PCB replacement tip
Carefully insert the paper feed PCB into the chassis, ensuring that the two paper feed PCB metal
tabs sit in the open tab holders in the chassis.
Figure 6-46 Paper feed PCB removal and replacement (3 of 3)
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C7085-90921 Chapter 6 Removal and replacement 185
Fusing motor (M1)
To remove the fusing motor
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Remove the fusing assembly.
4Remove the screw shown in callout 1, and remove the black plastic piece.
5Disconnect connector J102 from the paper feed PCB.
6Remove the screw that secures the white cable trough to the chassis (callout 2).
Figure 6-47 Fuser motor removal and replacement (1 of 2)
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186 Removal and replacement C7085-90921
7Slide the cable trough and cables out from the chassis.
8Remove the screw securing the plastic gear cover, as shown in callout 3, and then remove the
cover.
9Remove the three fuser motor screws shown in Figure 6-48.
10 Carefully pull to remove the fuser motor and free the cable from the cable trough.
Figure 6-48 Fuser motor removal and replacement (2 of 2)
C7085-90921 Chapter 6 Removal and replacement 187
Paper path pick-up motor (M2)
Note Turn the printer off, wait five seconds, and then unplug the printer.
1Remove the top cover.
2Remove the left side cover.
3Disconnect the paper path motor connector (J109) from the paper feed PCB and remove it from
the cable trough.
4Remove the two screws on both sides of the paper path motor shown in Figure 6-49.
5Remove the paper path motor by sliding the motor back and then out to clear the gear on the
motor.
Figure 6-49 Paper path motor removal and replacement
188 Removal and replacement C7085-90921
Paper pick solenoid (SL2)
To remove the paper pick solenoid
1Remove the top cover.
2Remove the left side cover.
3Disconnect the solenoid connector (J106) from the paper feed PCB, and free the cable from
the cable stays. Note the cable path when removing the cable.
4Remove the screw (callout 1) and e-clip (callout 2) that hold the solenoid assembly in place,
and then remove the solenoid assembly. For HP Color LaserJet 4500 printers with serial
numbers xxH or higher and HP Color LaserJet 4550 printers, also remove the screw shown in
callout 3 to remove the solenoid assembly.
Replacement tip
CAUTION When reinstalling the solenoid assembly, make sure that the flat parts of the Tray 2 pickup rollers are
down and that the plastic spring-loaded gear is fully engaged.
Figure 6-50 Paper pick solenoid removal and replacement
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C7085-90921 Chapter 6 Removal and replacement 189
ITB cleaning roller clutch (CL3)
To remove the ITB cleaning roller clutch
1Remove the top cover.
2Remove the left side cover.
3Remove the screw securing the metal CL3 cover plate shown in callout 1, and remove the plate.
4Unplug the connector from the cleaning roller clutch.
5Using needle-nose pliers, remove the e-clip and the gear shown in callout 2.
6Using needle-nose pliers, remove the e-clip and ITB cleaning roller clutch shown in callout 3.
Figure 6-51 ITB cleaning roller clutch removal and replacement
CAUTION Make sure that the clutch assembly gears are correctly reinstalled. For older printers, the gear
alignment marks should be offset by one gear tooth as shown in Figure 6-51; for newer printers, the
gears, which have a double line, should be aligned.
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190 Removal and replacement C7085-90921
ITB clutch (CL2) assembly
To remove the ITB clutch assembly
1Remove the top cover.
2Remove the left side cover.
3Remove the ITB cleaning roller clutch.
4Remove the screw shown in Figure 6-52 and remove the plastic shroud.
Figure 6-52 ITB clutch assembly removal and replacement (1 of 2)
5Disconnect the cable from the clutch assembly.
6Remove the three screws shown in Figure 6-53 and remove the clutch assembly.
Figure 6-53 ITB clutch assembly removal and replacement (2 of 2)
C7085-90921 Chapter 6 Removal and replacement 191
CAUTION Make sure that the clutch assembly gears are correctly reinstalled. For older printers, the gear
alignment marks should be offset by one gear tooth as shown in Figure 6-51; for newer printers, the
gears, which have a double line, should be aligned.
For proper operation, ensure that the ITB clutch (CL2) is connected to J103 on the Paper Feed PCB
and that the ITB cleaning roller clutch (CL3) is connected to J104.
192 Removal and replacement C7085-90921
Transfer roller cam clutch (CL4)
To remove the transfer cam clutch
1Remove the top cover.
2Remove the left side cover.
3Disconnect the connector (J105 at the Paper Feed PCB) from the clutch.
4Remove the e-clip shown in Figure 6-54 with needle-nose pliers and remove the clutch.
Figure 6-54 Transfer roller cam clutch removal and replacement
Replacement tip
For proper operation, ensure that the cable is connected to J105 on the paper feed PCB.
C7085-90921 Chapter 6 Removal and replacement 193
Left side gears
To remove the left side gears
1Remove the top cover.
2Remove the left side cover.
3Remove the fusing assembly.
4Remove the screw shown in callout 1, Figure 6-47 on page 185 and remove the black plastic
piece.
5Disconnect all connectors from the paper feed PCB and free the cables from the cable stays.
6Remove the screw securing the gear cover and remove the cover shown in callout 3, Figure 6-47
on page 185.
7Remove the fuser motor.
8Remove the paper path motor.
9Remove the three clutches: CL2, CL3, and CL4.
10 Remove the four screws (callout 1, Figure 6-55 on page 194) and remove the sheet metal over
the gears.
11 Remove the one or two screws (shown in callout 2, Figure 6-55 on page 194) and e-clip (shown
in callout 3, Figure 6-55 on page 194) that hold the solenoid assembly in place and then remove
the solenoid assembly.
12 Remove any e-clips or bushings necessary to remove the affected gears.
Left side gear replacement
1Install the back half of the large double gear shown in callout 1, Figure 6-56 with the small
portion of the gear (18T) facing outward.
2Install the two gears (shown in callout 2, Figure 6-56 on page 194) so they cover the back half of
the large double gear.
3Install the remaining gears and the front half of the large double gear so they appear as shown in
Figure 6-56 on page 194.
CAUTION When reinstalling the solenoid assembly, make sure that the flat parts of the pickup rollers are down
and that the plastic spring-loaded gear is fully engaged.
194 Removal and replacement C7085-90921
Figure 6-55 Left side gears removal and replacement (1 of 2)
Figure 6-56 Left side gears removal and replacement (2 of 2)
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C7085-90921 Chapter 6 Removal and replacement 195
Rear assemblies
Large right side fan
To remove the large right side fan
1Remove the formatter pan assembly.
2Remove the four screws as shown in Figures 6-57 and 6-58, and remove the fan shield.
3Disconnect the fan cable (J209) from the developing PCB.
4Unweave the fan cable from the cable stays.
5Release the plastic tabs at the top and bottom of the fan housing, and then slide the fan out.
Large right side fan replacement tip
Ensure that the fan cable is facing out and located in the lower corner.
Figure 6-57 Large right side fan removal and replacement (1 of 2)
196 Removal and replacement C7085-90921
Figure 6-58 Large right side fan removal and replacement (2 of 2)
C7085-90921 Chapter 6 Removal and replacement 197
Left side fan
To remove the left side fan
1Remove the top cover.
2Remove the left side cover.
3Remove the rear door.
4Disconnect the cable shown in callout 1, Figure 6-59.
5Remove the three screws from the left rear fan shield shown in Figures 6-59 and 6-60
(callout 2) and remove the fan shield.
6Disconnect the cable shown in callout 1, Figure 6-61.
7Remove the screw from the black plastic cover and remove the fan casing shown in
callout 2, Figure 6-61.
8Free the fan cable from the cable stay.
9Press out on the three plastic tabs and slide the fan out.
Left side fan replacement tip
Verify the label is facing out when replacing the left-side fan.
Figure 6-59 Left side fan removal and replacement (1 of 3)
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198 Removal and replacement C7085-90921
Figure 6-60 Left side fan removal and replacement (2 of 3)
Figure 6-61 Left side fan removal and replacement (3 of 3)
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C7085-90921 Chapter 6 Removal and replacement 199
Face-down assembly
To remove the face-down assembly
1Remove the top cover.
2Remove the left side cover.
3Remove the rear door.
4Remove the left side fan.
5Disconnect the bin full sensor shown in callout 1, Figure 6-62, and free the cable from the cable
stay.
6Remove the three screws from the face-down assembly shown in callouts 2 and 3, Figure 6-62.
7With your right hand, lift up slightly on the assembly to release the tab. Then, pull the assembly
out with your right hand while pushing the assembly to your right to release the plastic tab on
your left.
Replacement tip
Note the position of the black shoulder screw and metal bracket shown in callout 3, Figure 6-62.
Figure 6-62 Rear paper path assembly removal and replacement
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200 Removal and replacement C7085-90921
Internal assemblies
Cartridge carousel assembly
To remove the cartridge carousel assembly
1Remove the intermediate transfer belt and imaging drum cartridge. Protect the drum cartridge
from light.
CAUTION Exposure to light for more than 15 seconds can seriously damage the imaging drum.
2Remove the developers (toner cartridges) from the carousel and store them in a safe place.
3Remove the top cover (see “Top cover” on page 144).
4Remove the left side cover (see “Left side cover” on page 145).
5Remove the right side cover (see “Right side cover” on page 146).
6Remove the rear door (see “Rear door” on page 147).
7Remove the control panel and front right cover (see “Control panel” on page 153 and “Front
right cover” on page 155).
8Remove the rear cover (see “Right rear cover” on page 148).
9Remove the RFI shield (see “Radio Frequency Interference (RFI) shield” on page 156.
10 Remove the formatter assembly (see figure 6-63).
Figure 6-63 Cartridge carousel replacement - formatter pan assembly (1 of 6)
11 Remove the low-voltage power supply (see “Power supply” on page 173).
12 Remove the high-voltage power supply (see “High-voltage power supply” on page 174).
13 Remove the continuous toner level sensor assembly (see figure 6-64).
14 Remove the developer PCB assembly (see “To remove the developing PCB” on page 159), and
then remove the developer PCB mounting plate by removing the four screws of the plate
underneath the developer PCB assembly and lifting the plate out.
15 Remove the large fan housing and the large fan (see “Large fan housing” on page 178).
C7085-90921 Chapter 6 Removal and replacement 201
16 Remove the carousel drive assembly (see “Carousel drive assembly” on page 179).
Figure 6-64 Cartridge carousel replacement - continuous toner level sensor assembly (2 of 6)
17 Remove the laser shutter cover by pushing down on the silver tab in the middle and then rotating
the shutter toward the rear of the printer (see Figure 6-19).
18 Remove the carousel brake (see Figure 6-65).
Figure 6-65 Cartridge carousel replacement - carousel brake (3 of 6)
19 Remove the small fan housing assembly (see “Left side fan” on page 197).
20 Remove the face-down delivery assembly (see “Face-down assembly” on page 199).
21 Remove the interlock delivery rod (see Figure 6-66, callout 1).
202 Removal and replacement C7085-90921
Figure 6-66 Cartridge carousel replacement - face-down delivery rod (4 of 6)
22 Remove the door switch assembly (see “Top cover switch assembly” on page 161).
23 Remove the carousel grounding plate (see Figure 6-66, callout 2) and the carousel position
plate from the carousel mouting plate (see Figure 6-66, callout 3) on the printer’s right side.
24 Disconnect the cables going to PS-11 and the Continuous Toner Level Sensor (CTLS)
assembly, and remove the CTLS (see Figure 6-39).
25 Using a flat-bladed screwdriver, remove the clip securing the grounding cam and lift off the
grounding cam (see Figure 6-66, callout 4).
26 Remove the drum bushing assembly (see Figure 6-66, callout 5).
27 Remove the left-side carousel mounting plate.
28 Remove all visible screws from the carousel mounting plate on the printer’s right side (see
Figure 6-67).
Figure 6-67 Cartridge carousel replacement - right-side carousel mounting plate (5 of 6)
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C7085-90921 Chapter 6 Removal and replacement 203
29 Standing at the rear of the printer, lift the left side of the carousel while applying pressure toward
you to the rear cross-member plate. As soon as the carousel clears the right-side carousel
mounting plate, lift and rotate the carousel to your left to clear the assembly (see Figure 6-68).
Figure 6-68 Cartridge carousel replacement - lift out the cartridge carousel (6 of 6)
30 When the carousel is out of the engine, remove the 125-tooth gear, bearing and plastic spacer.
Install them into the replacement carousel.
31 Install the end of the carousel, opposite the 125-tooth gear into the holder. Rotate and move the
carousel down and to the right of the shroud. Apply pressure toward you on the sheet metal to
allow the carousel to drop into place.
32 Position the ends of the carousel so that the left side carousel mounting plate fits the plastic hub.
Make sure the plastic spacer is still on the shaft with the 125-tooth gear.
33 Assemble in reverse order of disassembly.
204 Removal and replacement C7085-90921
Toner catch tray and paper transport assembly
To remove the paper transport assembly
1Remove the fusing assembly.
2Remove the toner catch tray by pushing down on the clip in the middle and sliding it straight out
as shown in callout 1, Figure 6-69.
3Remove the screw from the rear of the assembly (callout 2).
4Slide the paper transport assembly toward your left until it stops. Tilt the assembly up to clear
the drive shaft coupler on your right and carefully work the assembly out of the printer.
Paper transport assembly replacement tip
Verify that all tabs are under the metal slots (two on the right, one on the left) and that the drive
shaft coupler engages properly.
Figure 6-69 Paper transport assembly removal and replacement
1
2
C7085-90921 Chapter 6 Removal and replacement 205
Paper pick rollers
To remove the paper pick rollers
Remove Tray 2. Determine which version of the printer you are working with, and follow the
instructions provided below, for the appropriate version of the printer.
For 4500 series printer serial numbers xxG or lower
The paper pick roller shaft is held in place with two white plastic clips.
Pull the paper pick roller shaft down until it releases from the two plastic clips shown in callout 1,
Figure 6-70.
For 4500 series printer serial numbers xxH or higher and 4550 series printrs
Note The paper pick roller shaft is held in place with two black plastic clips.
Do not remove the roller shaft unless you have to replace it. To replace the individual pick rollers,
rotate the shaft by hand so that the flat parts of the D-shaped rollers are facing up. Grasping the
center of the D-shaped roller with one hand, press down on the roller clip on the flat portion of the
roller with the other hand and pull it off of the shaft. If you need to remove the entire shaft, insert a
small flat-blade screwdriver into both of the plastic clips (as shown in callout 2, Figure 6-70) to
remove the roller.
Figure 6-70 Paper pick rollers removal and replacement
Paper pick roller replacement tip
When reinstalling the roller shaft, make sure that the flat parts of the D-shaped rollers are facing
down.
21
206 Removal and replacement C7085-90921
Star wheel assembly
To remove the star wheel assembly:
1Remove the ITB drawer.
2Open the drum drawer and remove the drum cartridge.
3Disconnect the spring as shown in (callout 1).
4Remove the linkage screw on the left (callout 2).
5Carefully pull the assembly forward to remove it from the shaft.
Star wheel assembly replacement tip
Insert the linkage over the shaft first.
Figure 6-71 Star wheel assembly removal and replacement
1
2
C7085-90921 Chapter 6 Removal and replacement 207
Transfer roller assembly
To remove the transfer roller assembly
1Remove the HVPS.
2Remove the left side cover.
3Remove the ITB drawer.
4Open the drum drawer and remove the drum cartridge.
5Remove the star wheel assembly.
6Using needle-nose pliers, remove the E-ring on each side of the shaft.
7Remove the gear.
8Remove the bushings.
9Slide the assembly out of the chassis.
Figure 6-72 Transfer roller removal and replacement
208 Removal and replacement C7085-90921
Cam shafts
To remove the cam shafts
1Remove the HVPS.
2Remove the left side cover.
3Remove the ITB drawer.
4Open the drum drawer and remove the drum cartridge.
5Remove the appropriate clutch or gear on the left side.
6Using needle-nose pliers, remove the e-rings from each end of the shaft being removed.
7Remove the bushings.
8Remove the shaft.
Note If the shaft is undamaged, then only the cams need to be replaced. Remove the screw from the cam
and replace only the cam.
Figure 6-73 Cam shaft removal and replacement
C7085-90921 Chapter 7 Troubleshooting 209
7Troubleshooting
Chapter contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
Troubleshooting process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .212
Pre-troubleshooting checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Troubleshooting flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Troubleshooting power-on. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Printer error troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Printer messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Alphabetical printer error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Numerical printer error messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226
Paper path troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Jams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237
Jam locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238
General paper-path checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Print media checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Jam recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Image formation troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Print density test and color checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Understanding color variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Color selection process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Customizing color output through printer drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
Adjusting color balance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Image defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Overhead transparency defects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Repetitive defects troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Interface troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
Communications checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
EIO troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268
AUTOEXEC.BAT standard configurations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Printer Job Language (PJL) commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
Control panel troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Control panel access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Printing a menu map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Information Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Paper Handling Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274
Configuration Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Printing Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
I/O Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
EIO Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Calibration Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281
Resets Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
210 Troubleshooting C7085-90921
Troubleshooting tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Embedded Web server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Printer configuration page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Event log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Hard disk file directory page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
Service mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Accessing the service mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Serial number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Transfer maintenance count. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Fuser maintenance count. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Color page count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Total page count. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Clear event log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Paper tray size functional test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
Diagnostics mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Entering diagnostics mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Formatter diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Engine diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
NVRAM initialization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
C7085-90921 Chapter 7 Troubleshooting 211
Introduction
This troubleshooting chapter assumes the reader has a basic understanding of the color laser
printing process. Explanations of each mechanical assembly, printer systems, and the basic theory
operation are found in Chapter 5. Do not perform any of these troubleshooting processes without
fully understanding the function of each mechanism.
This chapter contains the following sections:
Troubleshooting process includes a pre-troubleshooting checklist and a troubleshooting
flowchart. These tools contain information about common printer errors that can inhibit proper
operation or create print quality problems. These tools also include recommendations for solving
the cause of the error.
Printer error troubleshooting explains each control panel display message and suggests
recommendations for clearing the cause of each message. When the printer message indicates
a failure whose root cause is not obvious, use the printer error troubleshooting section and the
troubleshooting tools section found later in this chapter to solve the problem.
Paper path troubleshooting provides techniques to solve feed problems. Explanations
regarding print media checks, troubleshooting jams, and the differences between jams caused
by media and those caused by the printer are discussed.
Image formation troubleshooting provides print samples to help identify print defects, and
suggests methods for solving the problems.
Interface troubleshooting provides techniques for isolating communication problems to the
printer hardware, printer configuration, network configuration, or software application.
Control panel troubleshooting provides procedures for printing a menu map from the printer
control panel, and describes the control panel menus, the items within each menu, and the
possible values for the menu items.
Troubleshooting tools help isolate the cause of printer failures. This section includes
explanations of the printer configuration page, and the event log.
The service mode section provides procedures for entering service mode and performing
service-oriented tasks. These tasks include counts for entering the serial number, transfer
maintenance, fuser maintenance, color page, total page, clearing the event log, and various
printer tests.
The diagnostics mode section provides instructions on how to access and use the diagnostic
tools incorporated into the printer.
Diagrams provides graphical locations and tables for the printer’s internal assemblies and
sensors.
212 Troubleshooting C7085-90921
Troubleshooting process
The troubleshooting process requires both a mental and hands-on investigation of printer errors
and problems.
Use the pre-troubleshooting checklist to evaluate the source of the problem and to reduce the
number of steps required to fix the problem.
Use the troubleshooting flowchart to pinpoint the root cause of hardware malfunctions. The
flowchart guides you to the appropriate section of this chapter that provides steps for correcting
the malfunction.
Check the printer for the following before troubleshooting a specific printer problem:
Has regular maintenance been performed?
Are the maintenance units within their rated life?
Does the configuration page reveal any configuration errors?
Note The customer is responsible for checking consumable items, and using consumables that are in good
working condition.
Pre-troubleshooting checklist
The list below describes basic questions to ask the customer to help you quickly define the
problem(s).
C7085-90921 Chapter 7 Troubleshooting 213
WARNING! Electrical current is present in various printer parts whenever the printer is plugged in, even if the power
switch is in the standby position. Line voltage is exposed when the right cover and formatter pan are
removed.
Troubleshooting flowchart
The troubleshooting flowchart shown in Figure 7-1 highlights the processes that quickly solve printer
hardware problems. During its power on sequence, the printer verifies that its components are
operating correctly. If the printer fails to power on correctly, use the steps shown to troubleshoot the
failure.
Each heading depicts a major troubleshooting step. A “yes” answer to the questions allows you to
proceed to the next major step.
A “no” answer indicates that additional testing is needed. Proceed to the referenced location and
follow the directions for that area. After completing the additional testing, proceed to the next major
step.
Table 7-1 Pre-troubleshooting checklist
Environment Is the printer installed on a solid, level surface?
Is the power supply voltage within ± 10 volts of the specified power source?
Is the power supply plug inserted in the printer and the outlet? (Also verify that the
short power cord of the duplex unit is plugged into the printer, and the power
supply plug of the paper deck at the duplex unit is properly connected.)
Is the operating environment within the specified parameters, as listed in
Chapter 1 of this manual?
Is the printer exposed to ammonia gas, such as that produced by diazo copiers or
office cleaning materials?
Is the printer exposed to direct sunlight?
Media checks Does the customer use only supported media?
Is the media in good condition (no curls, folds, etc.)?
Is the media stored correctly and within environmental limits?
Media source Is the specified volume (or less) loaded into the media source?
Is the printer set to the correct media source?
Toner cartridge Are the color toner cartridges for each color correctly installed?
Drum cartridge Is the drum cartridge seated in the printer properly?
ITB and fusing Are the ITB and fusing units seated properly?
Doors and drawers Are the toner cartridge door, duplexer, drum drawer, and ITB drawer closed?
Condensation Does condensation occur following a temperature change (particularly in winter
following cold storage)? If so, wipe affected parts dry or leave the printer on for 10
to 20 minutes.
Miscellaneous Check for and remove any non-HP components (toner, memory modules, and
EIO cards) from the printer.
If hardware or software configuration has not changed, or the problem is not
associated with any specific software, contact the Customer Care Center (see
Chapter 1).
Remove the printer from the network and ensure that the failure is associated with
the printer before beginning troubleshooting.
Remove the printer from the network and ensure that the failure is associated with
the printer before beginning troubleshooting.
214 Troubleshooting C7085-90921
Figure 7-1 Troubleshooting flowchart (1 of 2)
C7085-90921 Chapter 7 Troubleshooting 215
Troubleshooting flowchart (continued)
Figure 7-2 Troubleshooting flowchart (2 of 2)
216 Troubleshooting C7085-90921
Troubleshooting power-on
Power-on check
1Verify that the printer is plugged into an active electrical outlet of the correct voltage.
2Verify that the power-on button is pushed in.
3Verify that the duplex unit short cord is plugged in to the printer.
4Make sure the fans are still running.
Note If the front panel display looks dark and an error message appears, check the ribbon cable between
the formatter and the DC controller.
5Remove any HP JetDirect or other EIO cards, then retry powering-on the printer.
6Make sure the control panel display is on.
7Check fuse in power supply (see Figure 7-36).
8Replace the power supply.
9Replace the interconnect PCB.
C7085-90921 Chapter 7 Troubleshooting 217
Printer error troubleshooting
Printer messages
The following tables explain messages that might appear on the printer control panel. Alphabetical
printer messages and their meanings are listed in Table 7-2, and numerical printer messages are
listed in Table 7-3.
Hint If a message requesting that you load a tray persists, or if a message indicating that a previous print
job is still in the printer’s memory persists, press [GO] to print or press [CANCEL JOB] to clear the job from
the printer’s memory.
Note Not all messages are described in the tables; those messages that are not listed are self-explanatory.
Some printer messages are affected by the AUTO CONTINUE and CLEARABLE WARNING settings from
the Configuration Menu on the printer control panel:
If CLEARABLE WARNING=JOB is set on the control panel, warning messages appear until the end
of the job from which they were generated.
If CLEARABLE WARNING=ON is set, warning messages appear until [GO] is pressed.
If an error occurs that prevents printing and AUTO CONTINUE=ON is set, the printer goes offline
for 10 seconds before it returns online.
If AUTO CONTINUE=OFF is set, the message appears until [GO] is pressed.
Alphabetical printer error messages
Table 7-2 Alphabetical printer error messages
ACCESS DENIED
MENUS LOCKED
Description:
Appears for approximately 5 seconds when a user has
attempted to select a menu value while the printer control
panel locking is enabled.
Action:
See the system administrator for access to the printer control
panel.
BAD DUPLEXER
CONNECTION
Description:
The duplex unit is not correctly installed. Action:
1. Verify that the power cord is connected to the duplex
printing accessory and the short power cord from the
duplex printing accessory is connected to the printer.
2. Turn printer off and then on.
3. If the error continues, verify that the duplex unit is
correctly installed.
4. If error persists, replace duplex unit.
CALIBRATION
EXECUTING
Description:
The printer is executing an internal color calibration. This
process should take approximately 90 seconds.
Action:
No action required.
CANCELING JOB
Description:
The printer is canceling the current print job. Incoming data
for the current job will be discarded.
Action:
No action required.
218 Troubleshooting C7085-90921
CANNOT DUPLEX
CLOSE REAR BIN
Description:
The printer cannot duplex because the rear output bin is
open.
Action:
1. Close the rear output bin door.
2. If the error message does not clear, turn the printer off
and then on.
CANNOT DUPLEX
CHECK REAR BIN
alternates with
CANNOT DUPLEX
CHECK PAPER
Description:
The printer cannot duplex because the rear output bin is
open or the media is not supported by the duplex unit.
Action:
1. Close the rear output bin.
2. If the error message does not clear, turn the printer off
and then on.
Verify that the media is supported by the duplex unit. See
“Supported media weights and sizes” in Chapter 1.
CHECKING PRINTER
Description:
The printer is performing an internal test. This process
should take approximately 30 seconds. The message
appears during the initiation of the engine test. When
finished, the printer goes online.
Action:
When the test has finished press [Go] to return the printer to
the READY state.
CLEARING PAPER
FROM PRINTER
Description:
The printer has jammed or was turned on and media was
detected in the paper path. The printer is attempting to clear
these pages.
Action:
No action required.
CLOSE FRONT DUPLEX DRAWER
Description:
The duplex drawer is not completely closed. Action:
Close the duplex drawer.
CLOSE MIDDLE FRONT DRAWER
Description:
The drawer that holds the intermediate transfer belt is open.
This drawer is called the ITB drawer, but is referred to as the
middle front drawer for end users. Switch SW1 (refer to
Figure 7-31) indicates the drawer is open. When the drawer
is closed, a plastic protrusion on the lower left corner of the
drawer pivots an arm allowing SW1 to toggle to the open
position.
Action:
1. Close the ITB drawer.
2. If the message persists, remove the printer’s left-side
cover and inspect the mechanical linkage that closes
SW1.
3. Refer to the wiring diagram to verify the wiring; the two-
wire connector should be firmly seated to SW1 and the
wiring harness should be firmly seated to connector
J1003 of the DC controller PCB.
4. If the message persists, use an ohmmeter to verify
functionality of SW1.
CLOSE UPPER REAR DRAWER
Description:
Switch SW5 (refer to Figure 7-29) monitors the closing of the
printer’s upper rear door (this door allows you to access the
fusing assembly). When the fusing door is closed, a tab on
the rear door pushes a door switch actuator that runs along
the left-side of the printer and closes SW5.
Action:
1. Close the upper rear drawer.
2. If the message persists, remove the printer’s left-side
cover and inspect the mechanical linkage of SW5 and
the lever.
(continued on next page)
Table 7-2 Alphabetical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 219
3. Refer to the wiring diagram and verify all connections
(J103 of the DC controller PCB and to SW5). Verify they
are firmly seated.
Verify that both the drum and ITB drawers are firmly closed;
closing these drawers also closes SW4 (see Figure 7-31).
Note Closing the rear door, the drum drawer, and the ITB drawers closes SW4 and SW5. When either of these
switches is open, the +24 V supply is disabled. This safety feature protects the operator from any high
voltages.
CLOSE TOP COVER
Description:
SW2 (refer to Figure 7-29) indicates whether or not the
printer’s toner access cover is closed. When the toner
access cover is closed, a lever is pushed down. This in turn
rotates a pivot forward, opening the top cover switch (SW2).
Action:
1. Close the top cover.
2. If the message persists, remove the printer’s top
assembly cover and verify all mechanical linkages
associated with SW2 (see Figure 7-29).
3. Verify that the connector on J1003 of the DC controller
PCB is firmly seated.
CLOSE UPPER FRONT DRAWER
Description:
The drawer that holds the imaging drum (the drum drawer) is
open. Switch SW3 (refer to Figure 7-31) indicates that the
drawer is open. When the drawer is closed, a plastic
protrusion on the lower left corner of the drawer pivots an
arm that allows SW3 to toggle to the open position.
Action:
1. Open the drawer and firmly push the drawer closed
using one hand in the middle of the drawer.
2. If the message persists, remove the printer’s left-side
cover and inspect the mechanical linkage that closes
SW3.
3. Refer to the wiring diagram and verify the wiring. The
two-wire connector should be firmly seated to SW3 and
the wiring harness should be firmly seated to connector
J1003 of the DC controller PCB.
4. If the message persists, use an ohmmeter to verify
functionality of SW3.
5. Verify FM3 (in the front of the Imaging drum drawer) is
functioning properly. The fan con-nects via J77 to J1022
on the DC Controller.
Note Closing the drawer also closes SW4 (the drum drawer switch). When SW4 is open, the +24 V supply is
disabled. This safety feature protects the operator from high voltages when the drum or ITB drawer is
open.
COLD RESET (4500)
-or-
RESTORE FACTORY SETTINGS (4550)
Description:
The cold reset power-up sequence has been entered. Action:
Most printer variables will reset to their factory default values.
CONTINUOUS PAGE
PRESS CANCEL JOB (4500)
Description:
The printer configuration page is being printed continuously. Action:
Press [Cancel Job] to terminate continuous configuration
page printing and return the printer to the READY state.
Note The 4550 has a paper path test that can be run from the Infomraiton menu.
DATA RECEIVED
Description:
The printer has received and processed data and is waiting
for a form feed.
Action:
Press [Cancel Job] and resend the last page of the job
making sure a form feed is sent with it, or press [Go] to feed
a new sheet of media through the printer.
Table 7-2 Alphabetical printer error messages (continued)
220 Troubleshooting C7085-90921
DENSITY SENSOR
OUT OF RANGE
alternates with
CLEAN DENSITY SENSOR
Description:
A density sensor out of range error was detected during a
color calibration.
Action:
The density sensor might be dirty. Inspect and clean the
sensor. See Cleaning the toner density sensor (page 85).
DIAGNOSTICS MODE
Description:
The extended diagnostics power-up key sequence has been
entered. Refer to the diagnostics procedures at the end of
this chapter.
Action:
No action required.
DRUM ERROR
REPLACE DRUM KIT
Description:
An error has been detected with a component of the printer
drum kit.
Action:
Replace the drum kit.
DRUM LIFE LOW
REPLACE DRUM KIT (4500)
-or-
DRUM LIFE LOW
ORDER DRUM KIT (4550)
Description:
Approximately 80% of the drum’s life has been consumed. Action:
Continue printing and order the drum kit. Drum replacement
will be required when the Drum Life Out message is
displayed.
DRUM LIFE OUT
REPLACE DRUM KIT
Description:
The imaging drum has reached the end of its expected life. Action:
Replace the drum kit.
DUPLEXER ERROR
CHECK DUPLEXER
Description:
An error has occurred in the duplex unit. Action:
1. Verify that the duplex unit is correctly installed.
2. Verify that the small power cord from the duplex unit is
plugged into the printer, and the power cord from the
AC outlet is plugged into the duplex unit.
EIO X
INITIALIZING YYY
alternates with
DO NOT POWER OFF
Description:
The EIO device in slot X is initializing. The YYY value will
increment every 10 seconds during this process.
Action:
No action required.
EIO X
NOT FUNCTIONAL
Description:
The EIO slot specified does not have a card installed or is
not functional.
Action:
No action required.
EVENT LOG EMPTY
Description:
SHOW EVENT LOG was selected from the Information
Menu, but the Event Log has no entries.
Action:
No action required.
Table 7-2 Alphabetical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 221
FUSER LIFE LOW
REPLACE KIT (4500)
-or-
FUSER LIFE LOW
ORDER KIT (4550)
Description:
Approximately 95% of the fuser’s life has been consumed. Action:
Continue printing, or replace the fuser kit. Fuser replacement
will be required in the near future.
Fuser Life Out
Replace Kit
Description:
The fuser has reached the end of its expected life. Action:
Replace the fuser kit.
INITIALIZING
Description:
The message appears when the printer is initially turned on. Action:
No action required.
INSTALL DRUM KIT
Description:
The drum kit is not installed or is incorrectly installed. Action:
Verify that the drum kit is correctly installed.
INSTALL TRAY 2
Description:
The printer cannot print until media is loaded into Tray 2. The
paper path for Tray 3 passes through Tray 2.
Action:
Insert Tray 2 into the printer so that printing from Tray 3 can
continue or start.
MEMORY FULL
STORED DATA LOST
Description:
The printer has no available memory. The current job might
not print correctly. Some downloaded fonts might have been
deleted.
Action:
Try printing simplified pages. If this does not resolve the
problem, add printer memory.
MEMORY SETTINGS CHANGED
Description:
The I/O buffering settings were changed by the printer
because there is not enough memory available to use the
previous settings.
Action:
No action required. However, adding printer memory might
prevent this from occurring.
MEMORY SHORTAGE
JOB CLEARED
Description:
The available memory was not enough to continue printing.
The remainder of the job was canceled.
Action:
No action required. However, adding printer memory might
prevent this from occurring.
MEMORY SHORTAGE
PAGE SIMPLIFIED
Description:
The printer’s adaptive data compression had to resort to
lossy compression to fit raster graphics in the available
memory. This has caused a data loss in the raster output.
Action:
1. Reduce the complexity of the page to improve the print
quality.
2. Adding memory will not correct this problem.
NO JOB TO CANCEL
Description:
[Cancel Job] was pressed but there is no active job or
buffered data to cancel. The printer automatically returns to
the READY state.
Action:
No action required.
Table 7-2 Alphabetical printer error messages (continued)
222 Troubleshooting C7085-90921
OFFLINE
Description:
The printer is offline and there are no error messages
pending.
Action:
Press [Go] to return the printer to the READY state.
PAGE CANNOT PRINT NOW
alternates with
RETRY WHEN PRINTING STOPS
Description:
An internal page has been requested while the printer is
printing an incoming job. Interrupting the job to print the
internal page would corrupt the job’s environment and
potentially cause the job to finish printing incorrectly after the
internal page is completed. Consequently, internal pages are
not permitted to interrupt jobs and can only be printed when
the printer is idle.
Action:
Retry the print job after the printer has completed the current
job.
PLEASE WAIT
Description:
The printer is in the process of purging data so that it can go
offline or into the menus.
Action:
No action required.
POWERSAVE ON
Description:
The printer is in PowerSave mode. This message is cleared
by pressing any key or by the receipt of a print job.
Action:
No action required.
PRESS GO TO PRINT
alternates with
PRESS SELECT TO
CHANGE TONER
Description:
The top cover was opened and closed when the printer was
not in toner cartridge replacement mode.
Action:
Press [Go] to resume printing or press [Select] to enter the
toner replacement mode.
PRINTER LANGUAGE NOT AVAILABLE
Description:
The printer received a request for a new language
(personality) that does not exist in the printer.
Action:
No action required.
PRINTING CALIBRATION
PAGE
Description:
The color calibration page is being printed. The printer
returns to the READY stage upon completion of this page.
Action:
No action required.
PRINTING CONFIGURATION PAGE
Description:
The configuration page is being printed. The printer returns
to the READY stage upon completion of this page.
Action:
No action required.
PRINTING FONT LIST
Description:
A typeface list for the available personalities is being printed.
The printer returns to the READY stage upon completion of
these pages.
Action:
No action required.
PRINTING MENU MAP
Description:
The printer menu map is being printed. The printer returns to
the READY state upon completion of this page.
Action:
No action required.
Table 7-2 Alphabetical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 223
PRINTING REGISTRATION PG
Description:
The registration page is being printed. The printer returns to
the READY state upon completion of this page.
Action:
No action required.
PRINTING LASERJET DEMO (4500)
-or-
PRINTING DEMONSTRATION (4550)
Description:
The demo page is being printed. The printer returns to the
READY state upon completion of this page.
Action:
No action required.
PRINTING LASERJET DEMO 2
(4500 only)
Description:
The demo page is being printed. The printer returns to the
READY state upon completion of this page.
Action:
No action required.
PRINTING ACCESSORIES
Description:
The accessories page is being printed. The printer returns to
the READY state upon completion of this page.
Action:
No action required.
PRINTING COLOR GUIDE
Description:
The color guide page is being printed. The printer returns to
the READY state upon completion of this page.
Action:
No action required.
PROCESSING JOB
Description:
The printer is processing the current job. Action:
No action required.
READY
Description:
The printer is online and ready to receive data, and no status
or device attendance messages are pending.
Action:
No action required.
REINSTALL TRANSFER BELT
Description:
This message occurs if you do not have the intermediate
transfer belt installed in the printer or if the home position
marks (on the ITB) are not detected by sensor PS5.
Note The intermediate transfer belt must be
rotating before PS5 is able to detect the
“home positioning” marks on the ITB.
Both the ITB and the imaging drum are
driven by the drum motor (M4).
Action:
1. Check SW1 (Figure 7-31) for correct operation and
make sure the cables are connected.
2. Verify that the ITB is installed in the printer.
3. If the ITB is installed and seated properly, verify that
PS5 is not damaged. PS5 is located on the ITB
assembly (see Figure 7-25). If the sensor appears
damaged replace the entire ITB assembly.
4. Clean PS5 (see Figure 7-25 for its location).
5. Verify all wiring within the ITB drawer. Note the
connection on the ITB assembly (located on the front,
lower, left-hand corner of the assembly). When the
drawer is closed, the connector “mates” with a
receptacle connector on the drawer. Verify the
connector and all wiring are in good condition. Make
sure there is no paper in the connector at the base of
the drawer.
6. Verify that the drum motor (M4) is rotating both the
imaging drum and the ITB. Place the printer in
diagnostic mode and run the drum test to verify drive
spindle movement for both the imaging drum and ITB.
7. If the imaging drum is not rotating, verify the imaging
drum connector is firmly seated into the connector J204
of the developing PCB.
Table 7-2 Alphabetical printer error messages (continued)
224 Troubleshooting C7085-90921
REMOVE PAPER TOP OUTPUT BIN
Description:
The top output bin holds 250 sheets of paper. Sensor PS9
(see Figure 7-21) along with its sensor flag detects the
height of the output paper stack. Perform the action items if
this message appears with no paper in the output bin.
Action:
1. Verify that the PS9 sensor flag and arm move freely and
its movement is not blocked (see Figure 7-21).
2. Verify PS9 is free of dust and debris (top assembly
cover must be removed to access sensor).
3. Verify all connectors are firmly seated. Refer to the
wiring diagram.
Note PS9 (a three-wire sensor) plugs into a through-wall connector on the printer’s chassis and then into a
14-pin wire harness, which plugs into J206 on the developing PCB (see Figure 7-21). All signals from
the developing PCB are routed to J201 on the developing PCB to J1017 on the DC controller PCB.
RESETTING MEMORY
Description:
The printer is executing a memory reset. The printer returns
to the READY state upon completion of this process.
Action:
No action required.
RESETTING VALUES
FINISHED
Description:
The color calibration density values have been reset to their
default values.
Action:
No action required.
RESTORING FACTORY SETTINGS
Description:
The printer is executing a RESTORE FACTORY SETTINGS
or a COLD RESET.
Action:
No action required.
SELECT LANGUAGE
Description:
The language selection power-up key sequence has been
entered. The printer will prompt the user to select a new
control panel display language once it has completed its
initialization process.
Action:
Select new language when prompted.
SERVICE MODE
Description:
The Service Mode power-up key sequence has been
entered. The printer will remain in Service Mode until [Go] is
pressed.
Action:
Press [Go] to end Service Mode.
TONER CMYK LOW
Description:
The toner cartridge specified is low on toner. This message
appears if TONER=LOW (default) is set on the printer control
panel in the Configuration Menu.
Action:
Printing will continue until a TONER OUT message appears.
To change the toner cartridge now, press [Select].
TONER CMYK OUT
alternates with
PRESS SELECT TO CHANGE TONER
Description:
The toner cartridge specified is out of toner. Action:
Press [Select] to enter the toner replacement mode. Press
[Go] to resume printing without changing the cartridge.
TONER CMYK LOW
alternates with
PRESS SELECT TO CHANGE TONER
Description:
The toner cartridge specified is low on toner and must be
replaced. This message appears when TONER LOW =
STOP is set on the front panel in the Configuration Menu.
Action:
Press [Select] to enter the toner replacement menu.
Table 7-2 Alphabetical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 225
TONER POSITION [COLOR] = [STATE]
Description:
Indicates the current state of a particular toner cartridge.
This message appears when [Select] is pressed while a
TONER LOW/OUT message appears.
Action:
If necessary, replace the specified toner cartridge.
TRANSFER KIT LOW
REPLACE KIT (4500)
-or-
TRANSFER KIT LOW
ORDER KIT (4550)
Description:
The transfer kit is near the end of its expected life. Action:
Continue printing and order Transfer kit. The transfer kit will
need to be replaced when the message Transfer Kit Out is
displayed.
TRANSFER KIT OUT
REPLACE KIT
Description:
The transfer kit has reached the end of its expected life. Action:
Replace the transfer kit.
TRAY X EMPTY
[TYPE] [SIZE]
Description:
The specified tray is empty but the current job does not
require this tray to complete the job.
Action:
No action required. However, loading the proper media type
and size into the tray will avoid this message in the future.
TRAY X LOAD
[TYPE] [SIZE]
Description:
The specified media type and size need to be loaded into the
requested tray.
Action:
Load the specified media type and size into the requested
tray. Press [Go] to override this request and cause the page
to be printed on different media.
TRAY X SIZE
[SIZE]
Description:
Media has been loaded into the specified tray. The most
recently configured size will be displayed with an asterisk
next to it.
Action:
1. [– Value +] might be used to view all possible media
sizes.
2. Pressing [Select] will select the currently displayed size.
Pressing [Go] will remove the message.
TRAY X TYPE
[TYPE]
Description:
Media has been loaded into the specified tray. The most
recently configured type will be displayed with an asterisk
next to it.
Action:
1. [– Value +] might be used to view all possible media
types.
2. Pressing [Select] will select the currently displayed
type. Pressing [Go] will remove the message.
TRAY X OPEN
Description:
The specified tray is not completely closed. Action:
Close the specified tray.
WARMING UP
Description:
The fuser is warming up. Printing will continue when the
fuser reaches the optimum temperature.
Action:
No action required.
WASTE TONER FULL
REPLACE DRUM KIT
Table 7-2 Alphabetical printer error messages (continued)
226 Troubleshooting C7085-90921
Numerical printer error messages
Description:
The waste toner full sensor PS13 detects a waste toner full
condition. A light receiver and light pipe arrangement, along
with a window in the drum assembly, look for a waste fill
condition. Verify that sensors and light pipes are not blocked.
Action:
1. Replace the drum kit.
2. Check the sensor, replace it if it’s defective.
Table 7-3 Numerical printer error messages
13.XX Jam
Note Refer to the jam troubleshooting section for the complete details about locating jams
(see page 237).
XX Description:
4500 4550
0 1 Jam in input feed area
1 5 Jam in fusing area
2 6 Jam in fusing area
3 10 Jam in duplex reversing unit
4 11 Jam in duplex feed unit
5 12 Jam in duplex paper feed area or ITB
drawer
6 13 Jam in duplex paper feed area or ITB
drawer
7 20 Jam in paper feed area or ITB drawer
8 21 Door open jam
9 23 Irregular jam in paper path
10 24 Paper in the paper path is too short
11 25 Paper in the paper path is too long
(see page 237 for complete details)
12 2 Paper did not clear input sensor in time.
alternates with
CHECK ALL REAR DOORS
Action:
1. Note the location of the leading edge of the first
jammed piece of media.
2. Note the jam message.
3. Note the location of the media.
Description:
Media is jammed in the rear paper path or rear
duplexing area.
Action:
1. Open the rear duplex door (if installed) and
remove any jammed media.
2. Open the upper rear door and remove any
jammed media.
alternates with
CHECK MIDDLE
FRONT DOORS
Description:
Media is jammed in the transfer belt area or media is
not being picked up properly.
Action:
1. Open the ITB drawer and remove any jammed
media.
2. Check for media between the transfer roller and
the fusing assembly.
alternates with
CHECK FRONT
DUPLEX DRAWER
Description:
Media is jammed in the front duplexing area. Action:
Open the duplex drawer and remove any jammed
media.
Table 7-2 Alphabetical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 227
13.0 Jams
Description:
Media is jammed in the front part of the printer
immediately after it is picked up.
Action:
1. Check to see if the white plastic tabs (located
inside the front of the trays under the
separation tabs) have fallen off in Tray 2 or Tray
3. (Note the position of the springs.)
2. Make sure that the correct media is loaded
properly in Tray 3, and that it is not overloaded.
3. Make sure that the two shipping locks have
been removed from the back of Tray 3.
4. Inspect the pick-up rollers for Tray 2; the flat
side of the “D” on the rollers should be parallel
to the paper.
5. Make sure that the roller spring underneath the
front of Tray 2 is secure.
13.1 Jam
OPEN MIDDLE FRONT DRAWER
alternates with
CHECK IN REAR OF DRAWER
Description:
A jam has occurred inside the ITB drawer area. (The
ITB drawer is also referred to as the middle front
drawer for end users.) The jam might be located in
the fuser area or between the transfer area and the
fuser.
Action:
1. Open the ITB drawer and carefully inspect for
any media.
2. Be sure to inspect the fusing area. You might
need to access the fusing area through the rear
door.
3. Remove any jammed media.
4. Make sure that the transfer roller is securely in
place.
20 INSUFFICIENT MEMORY
alternates with
PRESS GO TO
CONTINUE
Description:
More data has been received from the computer
than fits in the printer’s internal memory.
Action:
1. To continue printing, press [Go]. Only the
amount of data that fits in the printer’s internal
memory is printed.
2. To cancel the job, press [Cancel Job].
3. Add more memory to resolve the problem.
22 EIO X BUFFER OVERFLOW
alternates with
PRESS GO TO CONTINUE
Description:
The EIO buffer for the EIO card in slot “X” has
overflowed during a busy state.
Action:
1. The current data in the print buffer will be lost.
2. Press [Go] to resume printing and then resend
the job.
22 PARALLEL I/O
BUFFER OVERFLOW
alternates with
PRESS GO TO CONTINUE
Description:
Indicates the parallel buffer has overflowed. Action:
1. The current data in the print buffer will be lost.
2. Press [Go] to resume printing and then resend
the job.
Table 7-3 Numerical printer error messages (continued)
228 Troubleshooting C7085-90921
40 EIO X DATA ERROR
alternates with
PRESS GO TO CONTINUE (4500)
-or-
40 EIO BAD TRANSMISSION (4550)
Description:
A connection with the card in the specified slot has
been broken.
Action:
1. Check that all cables are connected to the EIO
ports and that the EIO board is seated properly.
2. If possible, print to another network printer to
verify the network is working properly.
Note All data in the print buffer will be
lost.
41.3 UNEXPECTED PAPER SIZE
alternates with
CHECK PAPER IN TRAY X (4500)
-or-
41.3 UNEXPECTED PAPER SIZE
alternates with
LOAD TRAY X [TYPE][SIZE] (4550)
Description:
A tray is configured for a specific paper size, but the
sheet loaded is a different size. This error often
occurs when the printer is multifeeding.
Action:
Load the requested size media in tray.
41.5 UNEXPECTED PAPER TYPE
alternates with
CHECK PAPER IN TRAY X
Description:
A tray is configured for a specific media type, but the
printer detects a different media type loaded. The
most common cause for this error is a jam at
registration plate (under the ITB) where the
customer does not remove the paper. The engine
tries to check the OHT sensor and receives an error
message.
Action:
1. Verify that the correct media type is loaded in
the input tray and the printer control panel is
configured correctly.
2. Clean the detection windows of OHT sensors
1 and 2 (see Figure 7-24).
49.ERROR XXXX
CYCLE POWER
Description:
Indicates that a firmware error occurred that caused
the processor on the formatter to abort operation.
This type of error can be caused by invalid print
commands, corrupt data, or invalid operations. In
some cases, electrical noise in the cable can corrupt
data during transmission to the printer. Other causes
include poor quality parallel cables, poor
connections, or home-grown applications. On rare
occasions, the formatter is at fault, which is usually
indicated by a 79 Service Error.
Note See the diagram on page 229 for
help with troubleshooting 49
errors
Action:
1. Turn the printer off and on to reset the printer.
2. Verify that all cables are connected.
3. Cancel all print jobs then resend. Try to isolate
any offending print job.
4. Delete the print job from the Windows spooler
or from the print server.
5. If the formatter pan assembly or DC controller
was removed, make sure the ribbon cable
between the DC controller and the interconnect
PCB is connected.
Note The printer control panel will
display 49 (FFFF) and the
display will be dark if the ribbon
cable is not connected.
6. To verify that the formatter is functioning
properly, run the formatter tests available in the
diagnostics mode (see page 300). If the
formatter passes, the formatter is not defective.
DO NOT replace the formatter.
Table 7-3 Numerical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 229
Troubleshooting 49 errors
Table 7-3 Numerical printer error messages (continued)
230 Troubleshooting C7085-90921
49 ADAC or AFAC
Description:
Indicates that the printer is printing a PostScript file
using Windows 3.1 or 9x.
Action:
No action required.
49 FF01 to FF05
Description:
An NEC firmware ROM error has occurred. Action:
Replace the firmware.
49 FF02
Description:
Unsupported EDO memory has been installed. Action:
Remove unsupported memory.
49 04CC
Description:
Indicates a media timing issue. This occurs when
printing multiple copies of transparencies or heavy
or glossy media with either the PCL or PostScript
drivers. Or it could indicate a timing mismatch
between the engine and formatter.
49 04E7
Description:
Occurs during decompression of the strip buffers
when the end of the strip marker is missing. This is
triggered by one of the following: 1) Marker is
corrupt; 2) Strip buffer size given to HiLite is too
small; 3) Strip buffer size given is too large.
Note This error is primarily associated
with the firmware and should not
require a new formatter.
49 04FF
Description:
A large print job (800 to 1200 pages) or complex
graphics can cause the printer to quit printing.
Action:
Two courses of actions are available:
Determine the page that is causing the failure.
If there is an image on the page, try to move
the image down on a portrait page or left on a
landscape page to move the image out of the
strip that is failing. The movements will need to
be very small so as not to cause the next strip
to fail.
Put the printer in Lossy mode with a sequence
of PJL commands. (Lossy compression is the
process of compressing a file such that some
data is lost after the file is compressed and
decompressed.) Use the following series of
commands to put the printer into Lossy mode:
ESC%-12345X@PJL
@PJL Default Service mode=HPBOISEID
@PJL Default Diagnostics=ON
@PJL Enter Language = PCL
ESC%-12345X@PJL
Esc*z9999P
Esc*z50P
Esc*z201X
(Continued on next page)
Table 7-3 Numerical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 231
To turn off Lossy mode once the file has
printed, use the following commands:
ESC%-12345X@PJL
@PJL Default Diagnostics=OFF
@JPL Default Service Mode=EXIT
@PJL EOJ
ESC%-12345X@PJL
Note Putting the printer in Lossy mode
might affect performance and
print quality
49 FFFF
Description:
Issue reported by life test when replacing the fuser.
This error might also occur during the boot cycle.
Action:
Replace the formatter.
49FFOX
Description:
This error message allows you to scroll through the
printer control panel to obtain all of the error
information.
Action:
No action required.
49 OBOA
Description:
A request is not understood. This error message is
generated when the I/O card does not support a
command that was sent to it.
Action:
Check the command being sent; the I/O card might
not support a particular feature.
49 OB22
Description:
This error message is generated when the I/O card
receives a control panel menu action that it does not
recognize.
Action:
Verify the action being sent.
50.x Fuser Error
Description:
The fusing assembly contains two heating bulbs, two
thermo-switches, and two thermistors. AC power is
provided to the fusing assembly via the DC power
supply, which is controlled by the DC controller PCB.
The thermistors monitor the temperature of the
fusing assembly and provide feedback to the DC
controller PCB to regulate the fusing temperature.
The two thermo-switches are wired in series with the
fusing bulbs, and “open” if the temperature exceeds
240°C (464°F).
X Description:
1 Low temperature error
2 Fuser warm-up service
3 High fuser temperature
4 Faulty fuser
5 Fuser voltage mismatch (verify that you have
NOT installed a 110V fuser in a 220V printer or
vice-versa).
6 Fuser heater cutoff
7 Fuser motor malfunction (see recommended
action for 50.7 Fuser error)
Action:
Note To visually check if the fusing
assembly is functional, you can
defeat the rear door interlock
switch (see Figure 7-33). Press
in on the white plastic above the
left rear corner of the fan, then
turn on the printer. If the fusing
bulbs and thermo-switches are
good, you should observe light
from the lower fusing bulb as the
printer warms up.
1. Turn the printer off and on to reset the printer. If
the error persists, try re-installing the fusing
assembly. If the error continues to persist,
proceed to step 2.
2. Turn the power off and remove the fusing
assembly. Measure the resistance between pin
3 and pin 4. The resistance should be between
6+/-2 ohms. If there is no continuity between
pins, it can be assumed that either a heating
bulb and/or a thermo-switch is “open.” Replace
the fusing assembly. If resistance limits are
acceptable, proceed to step 3.
(Continued on next page)
Table 7-3 Numerical printer error messages (continued)
232 Troubleshooting C7085-90921
3. Referring to Figure 7-36, measure the
resistance for both the upper and lower
thermistors. The resistance should be between
430K ohms and 310K ohms at room
temperature (25°C, 77°F). If the resistance
exceeds limits, replace the fusing assembly. If
resistance is within limits proceed to step 4.
4. Verify the connectors at J1011 of the DC
controller PCB and J1 of the DC power supply
assembly are firmly seated.
5. Replace the power supply assembly.
50.7 FUSER ERROR
Description:
The fusing motor (M1) drives the fusing assembly,
the paper transport (web) assembly, ITB lift
mechanism, transfer roller, transfer roller lift
mechanism, and the face down output delivery drive
assembly. A 50.7 fuser error appears when PS6
detects no motion within the fuser. Photosensor PS6
is the fusing unit pressure switch shown in
Figure 7-27.
Action:
1. Power cycle the printer to try to clear the
message.
2. Remove the left-side cover of the printer. Verify
that the fusing motor (M1) connector is seated
firmly into J102 of the feed PCB.
3. Ensure that the connector at J110 of the feed
PCB is firmly seated (this connector contains
the wiring for PS6, which provides fuser-motion
feedback).
Note Closely inspect the mechanical
linkage. The gears along the
gear “drive” path can bind the
gears, which will prevent M1
from rotating.
4. If the error persists, Observe the drive shaft of
M1 (refer to Figure 7-31) while powering on the
printer. If this shaft DOES NOT rotate, your
failure is related to the motor drive circuitry.
Referring to the printer’s wiring diagram, verify
that connectors J102 and J106 of the feed PCB
are firmly seated. If the error still persists,
replace the fusing motor and the feed PCB in
sequence.
5. If the shaft rotates (both forward and reverse),
and the 50.7 fuser error appears, the cause of
the error is related to the motion feedback
circuitry. Remove the fusing assembly and
verify the sensor flag (see Figure 7-27) is in
good condition and functional. Verify the
connector at sensor PS6 (see Figure 7-27) is
firmly seated. Clean the sensor of dust and
debris. If the error persists replace sensor PS6.
51 LASER ERROR (4500)
-or-
51.X PRINTER ERROR (4550)
Description:
Indicates a beam detect error or laser failure. Action:
1. Turn the printer off and on to reset the printer.
2. Verify connectors J1102 on the laser driver
PCB and J1008 on the DC controller are
seated properly.
3. Verify connectors J551 on the beam detect
PCB and J1006 on the DC controller are
seated properly.
4. Replace the laser/scanner unit.
Table 7-3 Numerical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 233
52 SCANNER ERROR (4500)
-or-
52 PRINTER ERROR (4550)
Description:
Indicates that a scanner error has occurred. Action:
1. Turn the printer off and on to reset the printer.
2. Verify connectors J551 on the beam detect
PCB, J1103 on the scanner motor, and J1006
on the DC controller are fully seated and
connected correctly.
3. Replace the laser/scanner unit.
53.XY.ZZ
PRINTER ERROR
Description:
Indicates a memory error. If a DIMM caused the
error, the DIMM will not be recognized (configured).
X = MemoryType
0 = ROM
1 = RAM
Y = Device Location
0 = Onboard
1 = DIMM slot 1
2 = DIMM slot 2
3 = DIMM slot 3
ZZ = Error Number
0 = Unsupported memory
1 = Unrecognized memory
3 = Failed RAM test
Action:
1. Verify that the DIMM is installed correctly.
2. Turn the printer off and on to reset the printer.
3. Remove and replace the DIMM that caused the
error.
54.1 PRINTER ERROR
Description:
Indicates that an internal power failure has occurred. Action:
1. Turn the printer off, and then turn the printer
back on.
2. Replace the high-voltage power supply.
3. Check the fuser to ensure jams have not
occurred.
CAUTION 54.1 errors can be caused by
damaging the thermistor while
clearing fuser jams.
4. Make sure there is not a fluctuation in the
power supply to the printer. Check that the
electrical specifications (see Chapter 1) are
met.
5. Replace the low-voltage power supply.
54.2 PRINTER ERROR
Description:
Indicates that a problem exists with the carousel
assembly. Either the carousel is not rotating or the
sensor has failed. Drive motor (M3) provides drive
for the toner cartridge carousel. If motion is not
detected, a 54.2 error appears. M3 is a 6-phase
stepping motor and receives its drive signal from
J203 of the developing PCB. Photosensor PS10
monitors “movement” (and the position) of the toner
cartidge carousel. Different width tabs (four tabs,
one for each cartridge) on the left-end of the
(Continued on next page)
Action:
1. Turn the printer off and then on to reset the
printer.
2. Open the color toner door and look for an
obstruction. If necessary, remove the toner
cartridges individually by manually releasing
the carousel brake and rotating the carousel
around to each cartidge position and removing
the cartridges. Turn the printer off and on to
reset the printer.
(Continued on next page)
Table 7-3 Numerical printer error messages (continued)
234 Troubleshooting C7085-90921
carousel housing pass through PS10 to provide
positioning information. The black toner cartridge tab
is the home position. Toner cartridge position within
the carousel is monitored by PS11. If PS11 fails or is
improperly connected, a 54.2 error appears. Another
indicator of this is that the carousel starts to rotate
then stops immediately.
A 54.2 error message can also occur if the sensor is
installed backwards.
Note The printer CANNOT operate
with the top cover removed
unless the carousel brake has
been released or removed.
3. Verify the carousel drive motor wiring harness
is firmly seated into connector J203 of the
developing PCB (see Figure 7-38).
4. Verify PS10 (refer to Figure 7-31) is working
correctly and not excessively dirty (clean if
necessary) and that the wiring harness is firmly
seated into both the sensor assembly and
connector J206 of the developing PCB.
5. Verify PS11 is connected and functioning
properly.
6. Verify all connectors to the developing PCB and
the DC controller PCB are firmly seated.
7. Verify that the rotary drive assembly is working.
Replace it on older units with more than 50K of
life.
Note The following URL provides help
with cartridge installation and
removal: http://www.hp.com/go/
ljsupplies.
54.3 PRINTER ERROR
Description:
The printer is not receiving data back from the
density sensor (PS14). PS14 is located in the
bottom of the imaging drum drawer (refer to
Figure 7-30). During calibration routines, a series of
images are written on the imaging drum and the
densitometer measures the density of the image
(e.g. amount of toner that is placed into the drum).
These measurements provide the feedback to
ensure image quality is consistent throughout the life
of the consumable.
Action:
1. Verify the densitometer is clean; perform the
toner density sensor cleaning procedure in
Chapter 7 of the online user guide.
2. Inspect the density sensor wiring harness for
damage. The harness runs from the density
sensor through the left-side upper control arm
of the imaging drum drawer to J1010 of the DC
controller PCB. Verify that the cable is firmly
seated into the J1010 of the DC controller PCB.
3. If the error persists, replace the density sensor
assembly.
54.4 PRINTER ERROR
Description:
Optional equipment is not recognized. Action:
Turn the printer off and on to reset the printer.
54.5 PRINTER ERROR
Description:
Indicates a waste toner sensor malfunction. Action:
1. Turn the printer off and on to reset the printer.
2. Remove the drum cartridge and clean the
waste toner detection window with a dry cloth.
3. Clean the waste toner sensor unit at the printer
side with a dry cloth.
4. Check the light guide and clean it if necessary.
Replace the light guide if the ends are scarred.
5. Reconnect the waste toner sensor unit
connector and the DC controller PCB
connector (J1009) correctly.
6. Replace the waste toner sensor (PS13).
Table 7-3 Numerical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 235
54.6 PRINTER ERROR
Description:
The OHT sensor has reported an error condition.
This can be caused by contamination in the
connectors, a blocked sensor, or a defective sensor.
See Figure 7-24 for the sensor locations.
Action:
1. Remove the ITB and verify that the OHT sensor
prism is in place.
2. Lift the registration flap and verify that the OHT
sensor is not blocked.
3. Remove the ITB drawer and inspect the drawer
connectors for contamination such as a piece
of paper.
4. If the error persists, verify that all connectors
are firmly seated.
5. Replace ITB drawer.
55 DC CONTROLLER ERROR
Description:
The print engine is not communicating with the
formatter. The communication link between the
formatter and DC controller was lost. This can occur
due to a timing error or intermittent connection
between the formatter and DC controller.
Action:
1. Turn the printer off and on to reset the printer.
2. Reseat the connectors between the formatter
and DC controller.
3. Only if the error persists, replace the DC
controller making sure to perform the
calibration and color plane alignment
procedures.
57.1 FAN FAILURE
Description:
The printer detected that the fan (an exhaust fan
located in the upper, left rear corner of the printer,
refer to Figure 7-34) was not rotating. This fan
operates off +24Vdc and is enabled by the DC
controller PCB’s microprocessor.
Action:
1. Turn the printer off and on to reset the printer.
Visually check to see if the fan is rotating (if you
cannot see any rotation, place your hand over
the outlet vents to see if exhaust air is moving).
2. Remove the printer’s left-side cover. Check to
see if anything is preventing the fan from
rotating freely.
3. Verify that the fan’s connector is firmly seated
into connector J208 of the developing PCB.
4. If the error persists, replace the fan.
57.2 FAN FAILURE
Description:
The printer detected that the fan (an exhaust fan
located in the upper, right rear corner of the printer,
refer to Figure 7-34) was not rotating. This fan,
operates off +24Vdc and is enabled by the DC
controller PCB’s micro-processor.
Action:
1. Turn the printer off and on to reset the printer.
Visually check to see if the fan is rotating (if you
cannot see any rotation, place your hand over
the outlet vents to see if exhaust air is moving).
2. Remove the printer’s left-side cover. Check to
see if anything is preventing the fan from
rotating freely.
3. Verify that the fan’s connector is firmly seated
into connector J208 of the developing PCB.
4. If the error persists, replace fan.
57.3 FAN ERROR
alternates with
CLOSE UPPER FRONT DRAWER
Description:
The intake fan is located in the front, center of the
drum drawer (refer to Figure 7-32). (The drum
drawer is referred to as the upper front drawer for
end users.) Fan rotation stops when the drawer is
opened. A fan error message appears when fan
motion is NOT detected by the DC controller’s
(Continued on next page)
Action:
1. Turn the printer off and on to reset the printer.
Due to the difficulty of observation, listen to
hear if the fan is rotating.
2. Verify FM3 connector 27 (callout #3 in
Figure 7-32) is not damaged or broken.
(Continued on next page)
Table 7-3 Numerical printer error messages (continued)
236 Troubleshooting C7085-90921
micro-processor if the drawer is closed and the
printer is not in PowerSave mode.
3. Verify the fan connector is firmly seated into
connector J1022 of the DC controller PCB.
4. If the error persists, replace the fan.
62 NO SYSTEM
Description:
Indicates there is a printer firmware problem. Either
there is no firmware DIMM installed or the DIMM has
failed. If the formatter was just replaced, make sure
all DIMMs have been moved from the old formatter
to the new one.
Action:
1. Turn the printer off and on to reset the printer.
2. Reseat the firmware DIMM, making sure it is in
the slot surrounded by a white line with the text
“ROM ONLY IN THIS SLOT.”
62.X PRINTER ERROR
Description:
Indicates that a problem exists with the internal
memory.
X = Description
0 = Internal memory
1-3 = DIMM slots 1 through 3.
Action:
1. Turn the printer off and on to reset the printer.
2. Reseat and then replace the DIMM.
3. Replace the formatter board.
62.M BAD MPTR
Description:
The firmware ran out of memory trying to build the
static entity directory.
Action:
1. Check printer settings to determine which
values have been changed.
2. Clear the message by pressing [Go].
68 NVRAM ERROR
CHECK SETTINGS
Description:
One or more settings saved in the non-volatile
storage device are invalid. Some settings might have
been reset to factory defaults.
Action:
1. Check printer settings to determine which
values have been changed.
2. Clear the message by pressing [Go].
68 NVRAM FULL
CHECK SETTINGS
Description:
Indicates that a non-volatile storage device is full.
Some settings might have been reset to factory
defaults.
Action:
1. Check printer settings to determine which
values have been changed.
2. Clear the message by pressing [Go].
79 SERVICE (XXXX)
PRINTER ERROR
Description:
A hardware error has occurred.
X=Description
01XX = IO ASIC register error
02XX = video ASIC register error
03XX = IDE ASIC register error
Action:
1. Reseat the formatter.
2. Reseat the firmware DIMM.
3. Run formatter diagnostics.
4. Replace the firmware DIMM.
5. Replace the formatter.
80 SERVICE (XXXX)
EIO ERROR
Description:
A critical EIO failure has occurred. X indicates the
slot number of the device. XXXX indicates the error
type.
Action:
1. Turn the printer off and on to reset the printer.
2. Reseat the EIO card.
3. Replace the EIO card.
Table 7-3 Numerical printer error messages (continued)
C7085-90921 Chapter 7 Troubleshooting 237
Paper path troubleshooting
Jams
Jam error messages appear if paper fails to arrive at or clear the paper path sensors in the allowed
time. Dedicated paper sensors (PS2, PS7, PS3101, PS3103, and PS3104) detect whether paper is
present in the sensor and if the paper is fed normally (see Figure 7-3). When the control board
detects a jam, it immediately stops the printing process and displays the appropriate jam message
for the sensor that detects the jam.
Figure 7-3 Jam sensors (shown with the optional 500-sheet paper feeder and duplex unit installed)
1Registration paper sensor (PS2)
2Duplex paper-pick sensor (PS3104)
3Duplex pick-up sensor (PS3103)
4Reversed paper sensor (PS3101)
5Delivery paper sensor (PS7)
1
5
2
4
3
238 Troubleshooting C7085-90921
Jam locations
Use Figure 7-4 to troubleshoot jams in the printer. For instructions on clearing jams, see the
sections later in this chapter.
Figure 7-4 Jam locations (shown with the optional 500-sheet paper feeder and duplex unit installed)
1Tray 1 input area
2Transfer belt area
3Tray 2 input area
4Front duplex drawer area
5Tray 3 (500-sheet paper feeder) area
6Rear duplex cover area
7Fuser area
8Rear paper path area
6
4
2
1
5
3
8
7
C7085-90921 Chapter 7 Troubleshooting 239
Jam locations by error message
Use Figure 7-5 and Table 7-4 to troubleshoot jams by the error message received. For instructions
on clearing jams, see the sections later in this chapter.
Figure 7-5 Jam locations by error message
See the next page for the Color LaserJet 4550 associated error messages.
Table 7-4 HP Color LaserJet 4500 jam locations and associated error messages
11
1
3
4
5
6
7
8
9
10
12
13
2
14
113.11 Paper in the paper path is
too long. Check the Tray 1 area.
Check the entire paper path.
813.3 Jam in duplex reverse unit.
Inspect the rear of the duplex
unit and the duplex tray.
213.10 Paper in the paper path is
too short. Check the Tray 1 area.
Check the entire paper path.
913.2 Jam in fusing area. Check
the fuser assembly, output
assembly, and duplex unit.
313.9 Irregular jam in the paper
path. Check the Tray 1 area.
Check the entire paper path.
10 13.1 Jam in fusing area. Check
the fuser assembly, output
assembly, and duplex unit.
413.8 Door-open jam. Check the
rear door, duplex cover, and rear
output door.
13.7 Jam in paper feed area.
Check the entire paper path.
Loose toner or paper dust on the
density sensor can cause this
error. Clean the sensor.
11 13.1 Jam. OPEN MIDDLE
FRONT DRAWER alternates with
CHECK IN REAR OF
DRAWER. Check the middle front
drawer. Check and pull out the
fuser.
513.6 Jam in duplex paper feed
area. Inspect the rear of the
duplex unit and the duplex tray.
12 13.1 Jam: Check in rear of
drawer. Check the rear of the
middle front drawer. Reseat the
transfer roller.
613.5 Jam in duplex paper feed
area. Inspect the rear of the
duplex unit and the duplex tray.
13 13.0 Jam in input feed area.
Check the input trays and duplex
unit.
713.4 Jam in duplex unit. Inspect
the rear of the duplex unit and
the duplex tray.
14 13.12 Paper did not clear the
input sensor in time.
240 Troubleshooting C7085-90921
Table 7-5 HP Color LaserJet 4550 jam locations and associated error messages
113.25 Paper in the paper path is
too long. Check the Tray 1 area.
Check the entire paper path.
813.10 Jam in duplex reverse unit.
Inspect the rear of the duplex
unit and the duplex tray.
213.24 Paper in the paper path is
too short. Check the Tray 1 area.
Check the entire paper path.
913.6 Jam in fusing area. Check
the fuser assembly, output
assembly, and duplex unit.
313.23 Irregular jam in the paper
path. Check the Tray 1 area.
Check the entire paper path.
10 13.5 Jam in fusing area. Check
the fuser assembly, output
assembly, and duplex unit.
413.21 Door-open jam. Check the
rear door, duplex cover, and rear
output door.
13.20 Jam in paper feed area.
Check the entire paper path.
Loose toner or paper dust on the
density sensor can cause this
error. Clean the sensor.
11 13.5 Jam. OPEN MIDDLE
FRONT DRAWER alternates with
CHECK IN REAR OF
DRAWER. Check the middle front
drawer. Check and pull out the
fuser.
513.13 Jam in duplex paper feed
area. Inspect the rear of the
duplex unit and the duplex tray.
12 13.5 Jam: Check in rear of
drawer. Check the rear of the
middle front drawer. Reseat the
transfer roller.
613.12 Jam in duplex paper feed
area. Inspect the rear of the
duplex unit and the duplex tray.
13 13.1 Jam in input feed area.
Check the input trays and duplex
unit.
713.11 Jam in duplex unit. Inspect
the rear of the duplex unit and
the duplex tray.
14 13.2 Paper did not clear the
input sensor in time.
Table 7-6 Explanation of alternating message
Check middle front doors Check middle front drawer.
Watch pick roller to ensure it is turning.
Check all rear doors Check duplex cover.
Check upper rear door and rear output door.
Check front duplex drawer Check front duplex drawer.
C7085-90921 Chapter 7 Troubleshooting 241
General paper-path checklist
Verify that media is correctly loaded in the input trays and that all length and width guides are set
correctly.
Clean the printer. Toner and paper dust in the paper path inhibit free movement of media through
the printer and block the sensors.
Vary the input and output selections of the printer to determine if the problem is associated with a
particular area of the printer.
Worn separation pads on the multipurpose tray can cause multifeeds. Check the condition of the
pickup rollers and customer replaceable feed roller. Bent separation tabs can cause misfeeds and
multifeeds. Replace the tray if necessary.
Defective paper tray switches can cause jams by communicating the wrong size paper to the
formatter.
Scraps of media left in the paper path can cause intermittent jams. Always check that the paper
path is clear when cleaning the printer and when clearing jams. Also, remove the fuser and
carefully check it for jam debris.
There are five areas in which jammed scraps can be difficult to find:
•The ITB drawer connector on the engine side.
•The OHT sensor under the registration plate.
•The fuser; remove the fuser to check it carefully.
•The center of the web transport before the fuser.
•Inside the ITB; Rotate the belt by rotating the two white knobs on either side of the ITB to clear
jam debris.
Print media checklist
Many print problems are caused by printing on media that does not meet specifications. The
HP LaserJet Printer Family Print Media Guide contains detailed information about media
specifications (see page 325 for ordering information). Refer to the following list for common media-
related printing problems.
Rough paper causes poor toner transfer and smeared print problems. Check that the paper
meets specifications for smoothness.
The printer handles only 60 to 176 g/m2 (16 to 47 lb) bond media when the media is less than or
equal to 148 mm (5.8 inches) wide. If the media is more than or equal to 148 mm (5.8 inches)
wide, the printer can handle only 60 to 135 g/m2 (16 to 36 lb) bond. Use transparencies that are
0.13 mm (5-mil) thick.
Paper that has absorbed moisture causes paper feed problems. When the printer is used in a
humid area, damp paper might be the cause of recurring paper feed and print quality problems.
Damaged paper, paper with ragged edges, or paper whose edges stick together cause jams.
Using paper that has already been through a laser printer or a copier can cause jams.
Print quality can degrade if media with a high resistivity is being used, specifically when
duplexing.
242 Troubleshooting C7085-90921
Jam recovery
This printer provides a jam recovery feature that allows you to set the printer to automatically
attempt to recover from jams. All pages affected by the jam will be reprinted if the jam recovery
feature is enabled. The options are:
ON Printer will attempt to reprint jammed pages.
OFF Printer will not attempt to reprint jammed pages.
Note During the recovery process, the printer might reprint several good pages that were printed before
the jam occurred. Be sure to remove any duplicated pages.
To enable jam recovery
1Press [MENU] until CONFIGURATION MENU appears.
2Press [ITEM] until JAM RECOVERY appears.
3Press [VALUE] until ON appears.
4Press [SELECT] to save the setting.
5Press [GO] to return the printer to the READY state.
To improve print speed, you might want to disable jam recovery. To disable jam recovery, select OFF
in step 3 above. If jam recovery is disabled, the pages involved in a jam will not be reprinted.
C7085-90921 Chapter 7 Troubleshooting 243
Image formation troubleshooting
The image formation system (Figure 7-6) consists of the following imaging units:
photosensitive drum cartridge carousel
laser/scanner
toner cartridges
intermediate transfer belt (ITB) unit
secondary transfer roller
Figure 7-6 Image formation
Before beginning image formation troubleshooting, check that the media meets the specifications
listed in the HP LaserJet Printer Family Print Media Guide.
Print density test and color checks
Use the configuration page to check the print density of the black, primary, and process color levels.
Solid black and color-filled areas on the configuration page demonstrate the ability to print at full
density. To print a configuration page, see page 287.
In addition to the items listed above, the configuration page provides the following information:
It helps isolate the problem to the software or the printer.
It shows that all colors print.
The following media-related items are responsible for many image formation and print-quality
defects:
rough paper
heavy paper
transparencies out of the specified thickness range
paper that has absorbed too much moisture from the atmosphere
room environment (humidity too high or low)
244 Troubleshooting C7085-90921
Understanding color variations
The printed output might not match the computer screen, and the colors printed on successive
pages might not match. While color variations are inherent in this printing method, they can indicate
changes in the printing environment, print media, or printer components.
Common causes of color variation
The following list outlines the major causes of color variations between computers, applications,
and output devices.
Halftone patterns produced on monitors and the types of patterns used in the print jobs are
different and might cause variations in the printed output.
The printed output differs from the image on the monitor because the monitor and the print
media have different reference values of black and white. The monitor screen has charcoal
gray for the black level, and the white on the monitor screen is actually blue. Black on the print
media is limited only by the fill capability of the printer, and most good quality paper has a very
high white level. In addition, phosphor (used in color monitors) and toner have entirely different
spectra characteristics and different color-rendering capabilities. Differences between output
are common. Blues generally match better than reds.
The color of the ambient light changes the perception of color. Fluorescent light lacks many
colors present in incandescent light, and the color range of natural light is broader than any
artificial light. When comparing color, choose a standard light source for reference and
understand that the perceived color will change as the light changes.
Long-term color variations occur as paper ages. Use high-quality paper and protect the paper
from sunlight to help minimize discoloration.
Environmental changes can cause color variation. The development process places a high
potential across an air gap to attract toner to the imaging drum. Changes in relative humidity
vary the point at which the toner travels to the imaging drum.
All consumable components have a finite life span. As these components reach the end of their
useful life, their ability to produce consistent print quality diminishes.
Paper roughness can cause colors to look different. Use standard paper.
Color selection process
The user selects the color in the application, but the operating system might convert or modify
some characteristics of the color before sending the information to the printer driver. The printer
driver might also modify color characteristics depending upon the selected output mode.
Any color characteristics not addressed by the printer driver or applications are set to the printer
default. The default color might not match the color the user selected.
Customizing color output through printer drivers
The printer driver, which is installed with your printer software, enables your software applications
to use the features of the printer. It also gives you customized control of color text, graphics, and
photos.
The method of using your printer driver depends on your computer’s operating system. For specific
instructions about using printer drivers, see the printer driver’s Readme file, which is included on
the printing system CD-ROM.
The following color control features are available only through your HP printer driver. See the
printer driver’s online Help for details about color settings and their effect on printed output.
C7085-90921 Chapter 7 Troubleshooting 245
Halftone options
Halftone options affect the resolution and clarity of your color output. You can select halftone settings
for text, graphics, and photos independently. The two halftone options are Smooth and Detail.
The Smooth option provides better results for large, solid-filled print areas. It also enhances photos
by smoothing out fine color gradations.
The Detail option is useful for text and graphics that require sharp distinctions among lines or colors,
such as images that contain a pattern or a high level of detail.
246 Troubleshooting C7085-90921
HP ColorSmart II
HP ColorSmart II is a set of technologies that enables optimal color output automatically for diverse
types of documents.
HP ColorSmart II utilizes object tagging and Standard RGB (sRGB) color technologies. Object
tagging allows optimal color and halftone settings to be used for different objects on a page (text,
graphics, and photos). The printer analyzes objects the page contains and intelligently uses
halftone and color settings that provide the best print quality for each object. Object tagging,
combined with optimized default settings, produces great color out of the box.
In the Windows environment, you will find the HP ColorSmart II Automatic and Manual settings on
the Color tab in the printer driver.
Color management options
Print in grayscale
Selecting the Print in Grayscale option in the printer driver allows you to print your document in
black and white. This option is useful for previewing preliminary copies of slides and hardcopy
output for color documents that will be photocopied or faxed.
Automatic color adjustment
The Automatic color adjustment feature of HP ColorSmart II (the default setting) optimizes the
color and halftones used for each element of a document. Automatic also provides additional color
options for application and operating systems that support color management systems. For more
information, see your printer driver online Help.
Note Automatic is the default setting and is recommended for printing all color documents.
Manual color adjustment
The Manual color adjustment feature of HP ColorSmart II allows you to adjust the color and
halftone modes for text, graphics, and photographs. To use the Manual color options from the Color
tab, select Manual, then select Options.
Halftone options
Halftone options affect the resolution and clarity of your color output. You can select halftone
settings for text, graphics, and photos independently. The two halftone options are Smooth and
Detail.
The Smooth option provides better results for large, solid-filled print areas. It also enhances
photos by smoothing out fine color gradations.
The Detail option is useful for text and graphics that require sharp distinctions among lines or
colors, or images that contain a pattern or a high level of detail.
Color map
The color map settings in the printer driver tell the printer how to interpret the data sent from a
software application into the final colors that the printer will print. The color map settings can be
adjusted to Screen match or Vivid.
Screen Match (sRGB — standard red-green-blue) prints colors that are optimized to match
RGB monitor colors. Use this setting to more closely match the colors on your screen.
A world-wide color standard originally developed by HP and Microsoft, sRGB is a common
C7085-90921 Chapter 7 Troubleshooting 247
color language for monitors, input devices (scanners, digital cameras), and output devices
(printers, plotters). It is the default color space used for HP products, Microsoft operating
oystems, the World Wide Web, and most office software sold today. sRGB is representative of
the typical Windows computer monitor today and the convergence standard for High-Definition
Television.
Note Factors such as the type of monitor you use and the room’s lighting can affect the appearance of colors
on your screen.
The latest versions of Adobe PhotoShop, CorelDRAW™, Microsoft Office, and many other
applications use sRGB to communicate color. Most importantly, as the default color space in
Microsoft Operating Systems, sRGB has gained broad adoption as a means to exchange color
information between applications and devices using a common definition that ensures typical users
will experience greatly improved color matching. sRGB combined with HP ColorSmart II improves
the user's ability to match colors between the printer, the computer monitor, and other input devices
(scanner, digital camera) automatically.
Vivid enhances the saturation of the printed colors to produce a vivid color appearance. For
more information, see your printer driver online Help.
Matching colors
The process of matching printer output color to your monitor is quite complex because printers and
computer monitors use different methods of producing color. Monitors display colors by light pixels
using an RGB (red, green, blue) color process, but printers print colors using a CMYK (cyan,
magenta, yellow, and black) process.
Several factors can influence your ability to match printed colors to those on your monitor. These
factors include:
Print media
Printer colorants (inks or toners for example)
Printing process (inkjet, press or laser technology for example)
Overhead lighting
Personal differences in perception of color
Software applications
Printer drivers
PC operating system
Monitors
Video cards and drivers
For most users, the best method for matching colors on your screen to your printer is to print sRGB
colors. The HP Color LaserJet 4550 uses HP ColorSmart II, which uses sRGB and automatically
optimizes color output. Keep in mind the above factors when colors on your screen do not perfectly
match your printed colors.
248 Troubleshooting C7085-90921
Four-color printing (CMYK)
Cyan, magenta, yellow and black (CMYK) are the inks used by a printing press. The process is
often called four-color printing. CMYK data files are typically used by and originate from graphic
arts (printing and publishing) environments. The HP Color LaserJet 4550 series printer is optimized
to print RGB colors for a good match to the screen, but will also accept CMYK colors through the
PostScript printer driver. By default, the HP Color LaserJet 4550 series printer interprets CMYK
data according to the Standard Web Offset Press (SWOP) standard. This standard defines how a
particular set of CMYK inks should behave. The printer performs a SWOP color map and internal
half-tones to emulate a SWOP CMYK press. Emulations for Dainippon Press (DIC) and Euro-
standard CMYK inks used in the Far East and Europe are also available, and can be selected from
the printer driver.
Matching PANTONE® colors
The PANTONE® Matching System colors are specified as CMYK colors as supported in many
graphics software applications. This color-matching system is useful for matching printer output to
a specific color (for example, a logo). See the documentation for your software application for
instructions on using PANTONE® colors.
For more information about using PANTONE® colors, see the Readme file for the PANTONE®
color-matching system included on the printing system CD-ROM.
Note Color settings, halftone settings, and print media affect the appearance of PANTONE® colors. To
optimize PANTONE®-certified colors, use the default PostScript 3 emulation driver settings and HP
LaserJet paper.
Automatic PANTONE ® calibration
Automatic PANTONE® calibration generates high-quality PANTONE® colors from the PANTONE®
color name automatically, providing the best possible color calibration in the HP Color LaserJet
4550 printers. An example of a PANTONE® name is: PANTONE® 286CVC. When printing
PANTONE colors, Automatic PANTONE® calibration is the default setting for HP Color LaserJet
4550 printers.
This feature automatically converts PANTONE® colors to optimal color values for the HP Color
LaserJet 4550 using the PANTONE® color name in the data stream sent to the printer.
Most application programs that support the use of PANTONE® colors for graphic objects will
include the PANTONE® name in the PostScript output, along with the color values assigned to the
object.
The HP Color LaserJet 4550 printer will recognize the PANTONE® name and substitute the
optimum color values for the printer based on color tables developed to provide the best possible
match for each specific PANTONE ® color within the printer’s color gamut.
No special actions are necessary in the application program or the driver to enable this feature. You
have the option of turning off Automatic PANTONE® calibration if you want to use application-
generated color values rather than HP-generated color values.
To turn off Automatic PANTONE® calibration:
In Windows, go to Properties, Advanced, and then Printer Features.
On a Macintosh, go to the CMYK Inks page of the driver interface.
C7085-90921 Chapter 7 Troubleshooting 249
These applications are known to generate PostScript files with graphic objects preserving the
PANTONE® name:
Adobe Illustrator 7 and 8
Adobe PageMaker 6.5
CorelDRAW 7, 8, and 9
Deneba Canvas 5 (see note)
Macromedia Freehand 7 and 8
Micrografx Designer
QuarkXpress 3 and 4
Note Subsequent versions of Deneba Canvas no longer generate compatible PANTONE® names. Microsoft
Publisher 2000 adds support for PANTONE® colors but does not preserve the PANTONE® name
necessary for this feature to work.
The Automatic PANTONE® calibration feature only applies to vector graphics, not picture (raster)
data such as scanned images and TIFF files. Adobe PhotoShop, for example, being a raster image
editor, is not on the above list of applications that support the Automatic PANTONE® calibration
feature.
WWW PANTONE® palettes for some raster image editor applications, such as Adobe PhotoShop, are
available on the Web at http://www.hp.com/support/lj4550. Once connected, select Downloads and
Drivers. Printer drivers, ICC color profiles, and sRGB color swatches are also available at this Web
address.
PANTONE® Application Palettes are available for:
Adobe Illustrator 4–8
PageMaker 5, 6, and 6.5
PhotoShop 3–5.5
CorelDRAW 6–9
Micrographics Designer 6–7
Macromedia Freehand 4–8
QuarkXpress (as EPS files) 3.3–4.04
Deneba Canvas 3.5–6.1
Fractal Design Painter 2–5.5
EPSF Charts
TIFF Charts
PANTONE® Color Drive
Text Format (ASCII)
Raw PostScript File
Adobe Acrobat
Vector graphics such as company logos created in one of the above applications (using palettes or
applications that preserve the PANTONE® name) can be imported into Microsoft Word, PowerPoint
and other MS Office applications. To do this, the color application must create an Encapsulated
PostScript (EPS) file of the image to be inserted as a file into the Office document using the insert file
function.
Note Cutting and pasting from the clipboard will not work. These tasks do not preserve the PANTONE®
name or the CMYK palette value.
250 Troubleshooting C7085-90921
Some of the PANTONE® colors will not match exactly. There are over 945 PANTONE® colors in
the PANTONE® Matching System. These colors were created using sixteen inks on a lithographic
printing press. Not all of these colors can be reproduced by a laser color printer because they are
out of a laser printer's four-color range. PANTONE® calibrates HP printers to provide the closest
match for all the colors we can reproduce and provide the colors closest to those we cannot
reproduce.
Note This feature requires the use of the PostScript 3 Emulation printer driver. It utilizes a function in the
PostScript language for describing custom colors like PANTONE® that is unique to PostScript and
not present in the PCL data stream. PANTONE® colors are used mostly in publishing environments
by applications such as QuarkXpress and Adobe InDesign that tend to use PostScript only.
Adjusting color balance
This printer features automatic color calibration to provide high-quality color output. In situations
that require critical color control, you can manually adjust the density balance of the printer’s four
toner colors.
CAUTION This procedure should only be performed by your network administrator. Performing this procedure
changes the color balance of the printer by altering halftones and affects all print jobs.
To adjust color balance
Step 1: Print a color balance calibration page.
The color balance calibration page (shown in Figure 7-7) displays current color settings and
provides a record of the printer’s initial settings before any adjustments are made.
1Press [MENU] until CALIBRATION MENU displays.
2Press [ITEM] until PRINT CALIBRATION PAGE displays.
3Press [SELECT] to print the color balance calibration page. The page consists of four color bars
(cyan, magenta, yellow, and black) and a box containing gray balance circles. The factory
default setting for each color is zero. The range of settings is -5 to +5.
Note Adjusting densities using the four color bars provides coarse color balance adjustments. After making
these adjustments, you can fine-tune color densities by adjusting the gray balance. (See step 7
for instructions.)
C7085-90921 Chapter 7 Troubleshooting 251
Figure 7-7 Color balance calibration page
Step 2: Adjust the cyan (C) density setting.
Examine the cyan density bar (C) on the color balance calibration page from a distance of 2 meters
(6 ft). If the center oval matches the background pattern more than the other ovals, the cyan density
does not need to be adjusted, and you should continue to the magenta (M) setting. If an oval left of
center or right of center matches the background more than the center oval, use the following steps
to enter the number:
1Press [ITEM] until CYAN DENSITY appears.
2Press the right side of the [VALUE] key to increase the value, or press the left side to decrease it,
until the number corresponding to the oval that most closely matches the background pattern
appears.
3Press [SELECT] to save the value. An asterisk (*) appears next to the selected setting.
Step 3: Adjust the magenta (M) density setting.
Examine the magenta density bar (M). If the center oval matches the background pattern more than
the other ovals, the magenta density does not need to be adjusted and you should continue with the
next step. If not, use the following steps to adjust the density:
1Press [ITEM] until MAGENTA DENSITY appears.
2Press the right side of the [VALUE] key to increase the value, or press the left side to decrease it,
until the number corresponding to the oval that most closely matches the background pattern
appears.
3Press [SELECT] to save the value. An asterisk (*) appears next to the selected setting.
Step 4: Adjust the yellow (Y) density setting.
Examine the yellow density bar (Y). If the center oval matches the background pattern more than the
other ovals, the yellow density does not need to be adjusted and you should continue with the next
step. If not, use the following steps to adjust the density:
1Press [ITEM] until YELLOW DENSITY appears.
252 Troubleshooting C7085-90921
2Press the right side of the [VALUE] key to increase the value, or press the left side to decrease it,
until the number corresponding to the oval that most closely matches the background pattern
appears.
3Press [SELECT] to save the value. An asterisk (*) appears next to the selected setting.
Step 5: Adjust the black (K) density setting.
Examine the black density bar (K). If the center oval matches the background pattern more than the
other ovals, the black density does not need to be adjusted and you should continue with the next
step. If not, use the following steps to adjust the density:
1Press [ITEM] until BLACK DENSITY appears.
2Press the right side of the [VALUE] key to increase the value, or press the left side to decrease it,
until the number corresponding to the oval that most closely matches the background pattern
appears.
3Press [SELECT] to save the value. An asterisk (*) appears next to the selected setting.
Step 6: Reprint the color balance calibration page. (See step 1.)
Step 7: Adjust the gray balance.
Note Adjusting densities using the gray balance pattern allows you to fine-tune color balance. This process
affects all four color bars.
Examine the gray balance circles in the box at the bottom of the color balance calibration page. If
the circle in the center most closely matches the background pattern, then the gray balance does
not need to be adjusted. If the circle does not match, use the following steps to adjust gray balance.
1Locate the gray circle that most closely matches the background. The magenta (M) and yellow
(Y) numbers associated with this circle indicate the optimum gray balance settings for these
colors.
2Adjust the magenta and yellow settings (yellow is horizontal and magenta is vertical) until the
gray circle is in the middle. Use the values from the bars above to select the value to be
entered.
3After making adjustments to the magenta and yellow settings, press [GO] to return the printer to
the READY state.
C7085-90921 Chapter 7 Troubleshooting 253
Image defects
Unless otherwise specified, all references in this section to horizontal or vertical directions of print
quality problems refer to problems found on A-4 and Letter-sized media. For more information on a
specific image defect, see the page numbers below each image in the following table.
Table 7-7 Image defect table
Background scatter2
(see page 254)
Banding and horizontal lines2
(see page 254)
Black lines
(see page 255)
Black or partially black pages
(see page 255)
Blank or white page(s)
(see page 256)
Blank spots Character voids
(see page 257)
Distorted image
(see page 257)
Dropouts
(see page 257)
Faded print, random faded
areas (see page 258)
Full page ghosting
(see page 258)
Gray background
(see page 258)
Irregular raised spots or stray
toner 2 (see page 259)
Light, dark, faded print
(see page 259)
Light black or no black print
(see page 259)
Loose toner
(see page 260)
Mottled or marbled output
(see page 260)
Random black spots
(see page 260)
Sharkskin
(see page 260)
Single color missing
(see page 260)
Sunburn
(see page 260)
Toner smear
(see page 261)
Vertical lines or streaks
(see page 261)
Wavy characters
(see page 262)
No
image
available
No
image
available
No
image
available
No
image
available
No
image
available
No
image
available
No
image
available
254 Troubleshooting C7085-90921
Additional defect information is found in the following sections:
Overhead transparency defects (see page 263)
Repetitive defects (see page 265)
Background scatter
The media does not meet HP specifications.
The toner cartridge is defective.
There is excess toner inside the printer. Clean the printer.
The transfer roller is dirty or worn. Generate a cleaning page.
Banding and horizontal lines
Banding occurs when solid fill areas show streaks or bands of shade variations. This can be
caused by:
Worn, damaged, or contaminated gears.
Consumables that are beyond their rated life.
Improper consumable storage.
If the problem persists:
Print a configuration page to check the life of the consumables. Replace any consumable that
is past its rated life.
Banding is more visible in some halftone patterns than others. Print a page using a halftone
pattern such as “banddiag” provided in the Color Smart selection in the printer driver. If the
defect occurs only once on a letter size sheet, try printing the pattern on a legal-size sheet.
Observe the following from the test sample:
•Check the spacing or “pitch” between the defects.
•Check to see if the defect spans all color planes.
•If the defect is in all color planes, does the defect produce a straight line through all color
planes or does it move from one color plane to the next?
•If the defect moves from one color plane to the next, measure the amount it moves. This
movement amount is called the “procession.” Keep in mind the print order is K-M-C-Y.
Measure the procession from K to M or M to C, not K to C.
CAUTION Do not expose the imaging drum to light for more than 15 seconds. The drum is light sensitive, and
exposure to light can cause permanent damage.
Banding — horizontal
The imaging drum might have been exposed to light. (See Sunburn on page 260.)
The ITB can accumulate contamination on its rollers causing a random mechanical banding. If
you notice buildup on the rollers, replace the ITB.
As the developer rotates, the gap between the imaging drum and the developer can vary
slightly. This can cause toner to be transferred unevenly and appear lighter or darker
approximately every 38 mm (1.5 inches). This defect is more apparent in secondary colors.
There is no workaround for this defect.
C7085-90921 Chapter 7 Troubleshooting 255
Banding — vertical
The doctor blade on the developer can develop notches over time. If you observe severe
notching, replace the developer.
As the imaging drum gets older, the charge roller doesn’t charge the imaging drum as well as it
used to. If you notice buildup or contamination on the charge roller, replace the imaging drum.
Black lines
The toner cartridge is defective.
The toner cartridge is not seated properly.
The fusing assembly is contaminated or damaged.
The static eliminator teeth are contaminated or defective.
The imaging drum is damaged or the waste toner collection in the drum is full. Replace the
imaging drum.
Black or partially black pages
Check for poor contact between the drum cartridge contact (for primary charging bias) and the
primary charging bias contact. To improve the contact, clean the contacts. If the problem persists
after cleaning or the contacts are deformed or damaged, replace them. If the contacts have
slipped off, adjust them correctly.
Check the drum cartridge (primary charging roller). If defective, replace the drum cartridge.
Check for poor contacts in the connectors. Reconnect the DC controller PCB connector and the
high-voltage PCB 2 connector correctly.
Check for a defective high-voltage PCB (primary charging bias output shortage). If defective,
replace the high-voltage PCB 2.
Check for a defective DC controller PCB. If defective, replace the DC controller PCB.
If ITB clutch was removed, check for proper timing.
The black toner cartridge is empty.
Make sure clutch CL2 is connected (plugged into the paper PCA).
This defect can be caused by improper timing on the ITB clutch gears. Make sure that the cams
are in sync. The two white gears on the left side of the printer (see Figure 6-47) should have two
timing marks pointing toward each other.
•Cams with a single line should be off one tooth clockwise on the right gear.
•Cams with a double line should be aligned.
256 Troubleshooting C7085-90921
Blank or white pages
Your software application is sending an extra page-eject command.
•Check the software’s printing configuration information.
There is a problem with the network configuration. Some sharing devices on networks might
generate a blank page as a separator.
•Check with the network administrator.
The printer might be feeding two or more pages at once because the paper is difficult to
separate.
The sealing tape has been left in the toner cartridge.
The toner cartridge is empty or defective.
The laser scanner door does not open properly.
•Remove and reseat the toner cartridge.
•Check the laser scanner shutter door for proper operation.
The toner cartridge guide is damaged, improperly positioned, or missing.
There is no transfer roller voltage.
•Perform the Half Self-Test Functional Check to check all other electrophotographic
processes.
•Replace the transfer roller if necessary.
The high-voltage connectors are mounted on the high-voltage power supply (HVPS) PCA and
protrude into the toner cartridge cavity.
•Check the springs for functionality. Clean if dirty; replace if defective or missing.
•The HVPS PCA is defective.
The DC controller PCA is defective.
There is no developing bias.
•Clean the HVPS contacts. With no developing bias charge, toner is not attracted to the
drum.
There is no drum ground path.
•Check the drum ground.
The laser scanner cable assembly is defective.
The page length and margins are not set correctly for the paper size. Verify that the ribbon
connector at J1307 of the HVPS is properly seated.
If the HVPS has been removed recently, verify that the ribbon connector from the DC controller
PCA to the HVPS is properly seated at both ends.
Verify that the photoconductive drum is rotating properly. Perform the drum diagnostic test to
visually observe if the drum is rotating or using a felt-tipped marker place an index mark on the
edge of the drum outside the image area. Turn on the printer (wait for drum rotation to occur),
and then look to see if the drum has moved. If the drum has not moved, investigate the
mechanical and electrical drum rotation circuitry and movement mechanisms.
The imaging drum shutter might not be retracting. Replace the imaging drum.
C7085-90921 Chapter 7 Troubleshooting 257
Character voids
Use media that meets HP paper specifications.
•The surface of the paper is too rough or too smooth for proper toner adhesion.
•The wrong side of the paper is being used for printing.
•The transparencies are not designed for proper toner adhesion.
•The transfer roller is defective.
•The laser scanner assembly is defective.
Colorless output (black only)
Make sure clutch CL2 is connected (plugged into the paper PCA).
This defect can be caused by improper timing on the ITB clutch gears. Make sure that the cams
are in sync. The two white gears on the left side of the printer (see Figure 6-47) should have two
timing marks pointing toward each other.
•Cams with a single line should be off one tooth clockwise on the right gear.
•Cams with a double line should be aligned.
Check for a defective development PCB. If defective, replace the development PCB.
Check for a defective DC controller PCB. If defective, replace the DC controller PCB.
Distorted image
The paper does not meet HP paper specifications or is stored improperly.
The printer’s operating environment does not meet HP specifications.
The connection of the cables to the laser scanner is poor.
The connection of the cables to the ECU is poor.
The laser scanner is defective.
The DC controller is defective.
Dropouts
The paper does not meet HP paper specifications.
The printer’s operating environment does not meet specifications.
The print density is set incorrectly. Change to a darker setting and retry printing.
The DC controller PCA is defective.
The high-voltage power supply PCA is defective.
The transfer roller is defective.
No
image
available
258 Troubleshooting C7085-90921
Faded print, faded areas, or faded vertical streaks
The message TRANSFER KIT LOW REPLACE TRANSFER KIT appears on the printer control
panel. Print out a configuration page to verify the remaining life of the transfer belt. Replace the
transfer belt if necessary.
The moisture content of your media might be uneven or too low. Use media from a different
source or from a new ream of paper.
If some areas of the paper reject toner, try using paper from a different source or from a new
ream of paper.
The media might be too rough and exceed media specifications. See Supported media
specifications on page 29. Do not use paper that exceeds specifications.
Check that the printing environment is within humidity specifications.
Faded print could result from low toner in a particular toner cartridge. If a TONER LOW or TONER
OUT message appears on the printer control panel, replace the appropriate toner cartridge.
Check to see if the transfer belt is contaminated. Use a lint-free cloth to clean any contaminants
from the transfer belt surface.
The connections into CL2 (ITB unit separation clutch) and CL3 (ITB cleaning roller separation
clutch) have been switched at the clutches, not on the PCB. (This typically shows a light black
print on the page.)
The toner cartridge is getting low on toner.
The toner density setting is not adjusted correctly.
The internal mirror or optics are contaminated.
The laser scanner is damaged.
The document scanner needs to be recalibrated.
There is a problem in the contact image sensor.
There is a problem in the formatter.
Full-page ghosting
Full-page ghosting occurs when an image prints in full color on one page, but a faded copy of it is
also seen on the following page.
Make sure that the top spring in the ITB drawer is properly connected.
Replace the ITB.
Ensure operation of the ITB Cleaning Roller Clutch (CL3).
If the imaging drum is near end of life, replace it.
If the toner cartridge is near end of life, replace it.
Gray streaks
The paper does not meet HP paper specifications or is stored improperly.
The printer operating environment does not meet specifications.
The toner density is set incorrectly.
The toner cartridge is defective.
There is excess toner inside the printer. Clean the printer.
The printer is printing on envelope seams. Move the text to an area away from seams.
The imaging drum is defective or at the end of its life. Replace the drum kit.
No
image
available
C7085-90921 Chapter 7 Troubleshooting 259
Irregular, raised spots or stray toner
Toner collected on the transfer belt can cause smudging on the back of the page. Smudges
commonly appear on the edges of pages after the media size is changed. The belt is self-
cleaning and the smudging will normally clear within a few pages.
Toner on the edge of the media is usually caused by toner collecting on the paper guides.
Inspect the paper guides and clean with a lint-free cloth if necessary.
Do not refeed paper that has already been through the printer. Re-feeding paper that has already
passed through the printer can contaminate the fuser causing stray toner defects.
Paper might print with blobs after warm-up. Print a few pages to resolve the anomaly.
Verify that all media is cleared from the paper path.
The fuser roller is damaged. Replace the fuser kit.
If one toner color is streaking, that toner cartridge has been damaged. Replace the toner
cartridge for the streaking color.
The paper does not meet HP paper specifications. Use media that meets HP media
specifications.
Light, dark, or faded print
The message TRANSFER KIT LOW REPLACE TRANSFER KIT appears on the printer control
panel. Print out a configuration page to verify the remaining life of the transfer belt. Replace the
transfer belt if necessary.
The moisture content of your paper is uneven or too low. Use paper from a different source or
from an unopened ream of paper.
Some areas of the paper reject toner. Use paper from a different source or from an unopened
ream of paper.
The paper is excessively rough. Use a smoother, xerographic paper.
The letterhead you are using is printed on rough paper. Try a smooth xerographic paper. If this
solves your problem, consult with the printer of your letterhead to verify that the paper used
meets the specifications for this printer.
Media does not meet the specifications for this printer. Only use media that meets the media
specifications for this printer.
The printer is operating in excessively humid or dry conditions. Verify that the printing
environment is within humidity specifications.
If a TONER LOW or TONER OUT message is displayed on the printer control panel, replace the
appropriate toner cartridge. If the problem persists, call for service.
Excess toner may have been deposited on the transfer belt. Use a lint-free cloth to clean any
excess toner from the transfer belt surface.
The laser scanner is defective.
The high-voltage power supply is defective.
Light black or no black print
The black toner cartidge is empty. Replace it.
The HVPS might be faulty.
The connections into CL2 and CL3 have been switched at the clutches, not on the PCB.
No
image
available
260 Troubleshooting C7085-90921
Loose toner
Loose toner is in the printer.
The toner cartridge is defective.
The paper is too smooth.
The driver setting for the paper type is wrong.
The fuser is defective.
Mottled or marbled output
Print a configuration page, and refer to the color blocks at the bottom of the page. Replace the
toner cartridge of the color or colors that are marbled.
Determine which toner color needs to be replaced by looking at the secondary colors on the self-
test page.
•If red and green are mottled, replace yellow.
•If red and blue are mottled, replace magenta.
•If green and blue are mottled, replace cyan.
Random spots
The paper does not meet HP paper specifications.
You are printing on the wrong side of the paper.
The printer requires cleaning with a cleaning page.
The toner cartridge is damaged.
The imaging drum is damaged.
Sharkskin (rough, mottled printing)
Use paper with lower resistivity.
Make sure the humidity and temperature are within specifications.
Do not use Automatic Duplex mode. Duplex manually or not at all.
Single color missing
Remove the toner cartridge and manually check the level of toner in the toner cartridge.
Check for a defective light pipe sensor. If defective, replace the toner level sensor.
Sunburn
The imaging drum might have been exposed to light. Symptoms of sunburn are streaked or blurred
lines across the length of the page (side-to-side on portrait, or top-to-bottom on landscape).
Print 50 to 100 pages on the imaging drum to remove the sunburn.
If sunburn symptoms are still occurring, allow the imaging drum to sit in a dark place for two to
three days.
If sunburn is severe (the symptoms don’t go away), replace the imaging drum.
CAUTION Do not expose the imaging drum to light for more than 15 seconds. The drum is light sensitive, and
exposure to light can cause permanent damage.
No
image
available
No
image
available
No
image
available
No
image
available
C7085-90921 Chapter 7 Troubleshooting 261
Toner smear
There is dirt on the paper.
The fusing rollers are dirty.
The paper does not meet HP specifications.
The toner cartridge is defective.
The fusing assembly is defective.
There is loose toner in the printer.
The static eliminator is dirty or is not grounded, allowing a static charge to remain on a page.
The DC controller PCA is defective.
Vertical lines or streaks
Check for a leak where light might be entering the printer.
Check for circumferential scars on the photosensitive drum. If scars are present, replace the
drum cartridge if the line goes through all colors.
Check for circumferential scars on the upper fusing roller. If scars are present, replace the upper
fusing roller if the line goes through all colors.
Remove the imaging drum and inspect main charger or imaging drum for a contaminant, such as
a fiber, if the line goes through all colors.
CAUTION Do not expose the imaging drum to light for more than 15 seconds. The drum is light sensitive, and
exposure to light can cause permanent damage.
Vertical black lines
The toner cartridge is defective.
The toner cartridge is not seated properly.
The fuser entrance is dirty.
The fuser has scratches on it.
This might be a repetitive defect. If so, the lines will repeat at a consistent interval down the page.
The printer needs to be cleaned.
There is a problem in the heating element.
Vertical white lines
If white lines or streaks appear only in the black areas of the printed media, print several
configuration pages to clear the anomaly. If this does not clear the problem, check the sleeve
surface to confirm the defect, then replace the black toner cartridge.
If white lines appear only in a particular color, try printing several configuration pages to clear the
error. If the error does not clear, check the sleeve surface to confirm the defect, then replace the
defective toner cartridge.
There is a lack of toner or the toner cartridge is faulty.
There is dirt in the laser path.
The fuser is defective.
A mirror in the laser scanner is dirty.
262 Troubleshooting C7085-90921
Wavy characters
Mechanical instability in the scanner mechanism or the optics can cause wavy characters.
Reprint the job to ensure that the problem persists.
If the failure remains, replace the laser scanner assembly.
C7085-90921 Chapter 7 Troubleshooting 263
Overhead transparency defects
Overhead transparencies can display any of the image quality defects shown in the previous
samples. In addition, because transparencies are pliable while in the print path, they are subject to
being marked by the media-handling components.
Note Allow transparencies to cool at least 30 seconds before handling them.
Make sure that “transparency” is checked as the media type in the Paper Tab in the printer driver.
Also, make sure that the media input tray is correctly configured for transparencies. When
Transparency is selected as the media type and ColorSmart II is selected on the Color tab, the
printer will use a color treatment optimized for projection.
If transparencies show lines and creases in the media and/or the printed output, compare the
defect against the repetitive defect ruler (page 266) to help isolate the cause to a particular
component.
Check that the transparencies meet the specifications listed in the HP LaserJet Family Print
Media Guide.
If the transparencies have spots or smudges, reprint them being careful not to touch the surface
of the media. Skin oils can contaminate transparencies, causing spots and smudges.
Small, random dark areas on the trailing edge of solid fill pages might be caused by
transparencies sticking together in the face up bin. Try printing the job in smaller batches.
Send transparencies only to the face-down output bin.
Transparencies created on the printer might look blurry, but they can still be used successfully on
reflective-type (portable) transparency projectors.
Dull or dark transparencies
If the transparency colors are dull or dark, ensure that the transparencies meet the specifications
for this printer (part number C2934A for Letter, and C2936A for A4).
The selected colors are undesirable when printed. Select different colors in your software
application or printer driver.
Spots and smudges appear in the background areas of transparencies when they are projected.
Oil from your hands can cause spots or smudges on transparencies. Reprint the transparencies,
being careful not to touch the surface of the transparencies.
You are using a reflective overhead projector. Use a standard overhead projector.
Incorrect image on transparencies
This might occur even though the correct media is loaded in the correct tray. Toner might not adhere
to the media and an image might show up on pages where it isn’t meant to appear. (See Full-page
ghosting on page 258.)
When this occurs on transparencies, the connections for the ITB cleaning roller (clutch 3) and for the
secondary transfer roller (clutch 4) might be reversed.
Repetitive defects on transparencies
Overhead transparencies that have repetitive defects spaced 131 mm (5.2 in) apart indicate a defect
on the upper fuser roller.
1Turn the printer off and unplug the printer, allow 30 minutes for the fuser to cool, and then remove
the fuser.
CAUTION Make sure to wait 30 minutes before removing the fuser. The fuser will be hot.
No
image
available
264 Troubleshooting C7085-90921
2Turn the fuser gears and inspect the surface of the upper fusing roller. If the roller has surface
defects (gouges), replace the fusing assembly.
Streaking on transparencies
If the transparencies have streaks, this could be the result of condensed wax from the toner making
its way onto the fuser assembly rollers during the fusing process. Try cleaning the fuser rollers
using the following process:
1Saturate a corner of a lint-free, static-free wipe with isopropyl alcohol.
2Open the alternate path door (the small door) at the back of the printer.
3Place the printer into calibration mode by opening and then closing the large door at the rear of
the printer, or by pulling a drawer open, and then quickly closing it.
4While the printer is calibrating, the fuser rollers are rolling. Place the wipe up against each
roller in turn, keeping it in place for five to 10 seconds.
C7085-90921 Chapter 7 Troubleshooting 265
Repetitive defects troubleshooting
Repetitive defects are defects that occur on the page. Most repetitive defects are caused by
problems with one of the following:
See page 266 for the repetitive defect ruler and Table 7-9 for the defect spacing chart.
CAUTION Do not expose the imaging drum to light, and be careful not to scratch or get fingerprints on the drum
surface during cleaning. Do not blow on the imaging drum.
Imaging drum defects
Causes:
Damage such as scratches or dents on the imaging drum. These usually appear as black or
white marks on the page.
Paper dust adhering to the imaging drum. These usually appear as white marks in the dark
printed areas of the page.
Exposure of portions of the imaging drum to light. This causes light sections in the printed
output. The life of the imaging drum is shortened by exposure to light.
Actions:
Print at least four configuration pages to determine if the defect repeats in the same horizontal
orientation.
Inspect the imaging drum for scratches, dents, or other damage. Replace if needed.
If the problem is dust, remove the dust with isopropyl alcohol applied with a lint-free, static-free
wipe. Try this only if the print defect is unacceptable and the only other alternative is replacing
the imaging drum.
Defects caused by exposure to light might clear up over time. If severe, replace the imaging
drum.
Table 7-8.
Developer roller
Charge roller
Cleaning roller
Transfer roller
Fuser
Imaging drum
Transfer belt
266 Troubleshooting C7085-90921
Repetitive defect ruler
Figure 7-8 Repetitive defect ruler
Color developer 30 mm (1.2 in)
Black developer roller 37 mm (1.5 in)
Transfer roller 53 mm (2.1 in)
Imaging drum 152 mm (6 in)
Fuser 131 mm (5.2 in)
ITB cleaning roller 40 mm (1.6 in)
Charge roller 40 mm (1.6 in)
First occurrence of print defect
C7085-90921 Chapter 7 Troubleshooting 267
Figure 7-9 Imaging drum exposed to light (proportions not to scale)
Table 7-9 Defect spacing chart
Consumable Roller Distance
Drum Charge roller 40 mm
(1.6 in)
Imaging drum 152 mm
(6 in)
Developer Black developer 37 mm
(1.5 in)
Color developer 30 mm
(1.2 in)
Fuser 131 mm
(5.2 in)
ITB ICL roller 40 mm
(1.6 in)
Transfer roller 53 mm
(2.1 in)
268 Troubleshooting C7085-90921
Interface troubleshooting
Communications checks
Note Communication problems are normally the customer’s responsibility. Time spent attempting to
resolve these problems might not be covered by the product’s Hewlett-Packard warranty.
Refer the customer to the network administrator for assistance in troubleshooting network problems.
If the printer is not connected to an MS-DOS-based host, proceed to Table 7-10, Communications
check.
EIO troubleshooting
If the printer contains an optional HP JetDirect print server, and you cannot communicate with the
printer over the network, verify the operation of the print server. Print an HP JetDirect configuration
page. If the message “I/O CARD READY” does not appear on the configuration page, see the
troubleshooting section of the HP JetDirect Print Server Software Installation Guide.
If the host system and printer still are not communicating, replace the formatter PCB and the EIO
card and reconfigure the printer. If the problem persists, a protocol analyzer might be needed to
find the source of the problem.
CAUTION HP LaserJet printers are not designed to work with mechanical switch-box products without proper
surge protection. These devices generate high transient voltages that cause permanent damage to
the formatter PCB. This circumstance is not covered by the Hewlett-Packard warranty.
Figure 7-10 HP EIO configuration page
Table 7-10 Communications check
Check Action
Is your computer configured
to the parameters described
in the configuration
instructions?
These parameters are required to communicate with the printer.
Verify that the configuration of the computer's communications
port matches these parameters.
Note: If these parameters are not set properly, an error might
display on the control panel.
C7085-90921 Chapter 7 Troubleshooting 269
AUTOEXEC.BAT standard configurations
Parallel DOS commands
Ensure that the AUTOEXEC.BAT file contains the following statements for parallel interface
communications:
MODE LPT1: ,,P
For MS-DOS version 4.0 and above:
MODE LPT1: ,,B
Note This example assumes that you are using parallel printer port LPT1. If you are using LPT2 or LPT3,
replace LPT1 in the example with the appropriate printer port.
Printer Job Language (PJL) commands
See the HP Printer Job Language Technical Reference Manual for a complete description of PJL
commands. This manual is available with the HP PCL/PJL Reference Set on CD-ROM, part number
5021-0337.
@PJL [Enter]
This command enables the specified printer language. If the printer does not receive this command it
enables the default language. This ensures the correct operation applications that do not support
PJL. The command syntax is:
@PJL [Enter] LANGUAGE = {PCL/PostScript} [<CR>] <LF>
UEL (universal exit language)
This command (also referred to as the universal exit language command) terminates the current
printer language and returns control to PJL. It performs the following actions:
• Prints all data received before this command.
• Performs a reset: <esc>E in PCL, <cntrl>D in PostScript.
• Turns control over to PJL.
This command is also a valid HP-GL/2 terminator.
The UEL command must be immediately followed by the “@PJL” command prefix. Characters or
control codes other than @PJL (such as <CR> or <LF>), enable the default language and process
the print job in that language. All jobs must begin and end with the UEL command. Besides entering
PJL, the UEL command has the same effect as the <esc>E command. However, the <esc>E
command should always be included to ensure backward compatibility.
@PJL COMMENT
This command designates the current line as a comment, which is ignored. The syntax is:
@PJL COMMENT <words> [<CR>] <LF>
@PJL INFO CONFIG
This command solicits a response to describe the installed options and allows the printer to
automatically configure the installed options as the applications require.
270 Troubleshooting C7085-90921
@PJL INFO ID
This command identifies the printer type to the host for reference when selecting printer drivers for
automatic installation. The command syntax is:
@PJL INFO ID <CR> <LF>
@PJL INFO USTATUS
This command queries the state of unsolicited JOB status. PAGE and TIMED status are not
supported. The syntax is:
@PJL INFO USTATUS <CR> <LF>
@PJL INFO PAGECOUNT
This command returns the number of pages printed by the engine.
@PJL JOB
This command informs the printer of the start of a PJL job and synchronizes the job status
information. The printer counts print jobs, including nested jobs, incrementing the job counter for
the @PJL JOB command and decrementing it for @PJL EOJ.
The printer accepts the NAME= parameter and returns the name string in the unsolicited JOB start
status message (if unsolicited job status is enabled). The printer transmits the unsolicited JOB
status message to every I/O channel that has enabled this function. This message’s format is:
@PJL USTATUS JOB <CR><LF>
START<CR><LF>
[NAME=<job name><CR><LF>]
<FF>
The printer resets the nested job counter whenever it switches the source to a different I/O
channel. This prevents a corrupt job on one channel from disrupting the activities on another
channel.
@PJL EOJ
This command identifies the end of a print job and is a hint for the I/O switching algorithm. The
printer counts nested jobs and recognizes job boundaries when the counter decrements to zero.
The printer ignores isolated EOJ commands. Each EOJ must be preceded by a JOB command.
@PJL ECHO
This printer supports the ECHO command which transmits its parameters over the I/O channel to
the host that issued the command.
@PJL USTATUS JOB=ON/OFF
This command enables or disables the JOB status for the I/O channel that delivers the command.
@PJL USTATUSOFF
This command disables the unsolicited JOB status for the I/O channel that delivered the command.
For this printer, it duplicates the function of @PJL USTATUS JOB=OFF, AND @PJL USTATUS
DEVICE=OFF.
Note All commands not supported by this printer’s PJL command set are returned with the message @PJL
XXXX<CR><LF>?<CR><LF>.
C7085-90921 Chapter 7 Troubleshooting 271
Control panel troubleshooting
Control panel access
Accessing the diagnostics for the control panel is a simple process. Hold down the left side of the
[ITEM] key (<--) and turn on the printer. Hold the key down until DIAGNOSTICS MODE appears on the
front panel, and then release the key. The front panel will change and display FORMATTER DIAGS
EXECUTE TESTS. Press the [MENU] key to switch between the formatter diagnostics and the engine
diagnostics. Press [ITEM] to scroll through the diagnostics available in each section.
A menu map helps you use the control panel menus. See the menu map sample that follows.
Printing a menu map
Printing a menu map can help you navigate through control panel menus.
Printing a menu map
1On the printer’s control panel, press [MENU] until
INFORMATION MENU appears.
2Press [ITEM] until PRINT MENU MAP appears.
3Press [SELECT] to print the menu map. The printer will return to the READY state.
Interpreting the menu map
The following sample illustrates the printer’s menu map.
Figure 7-11 4500 series menu map
1Information Menu
2Paper Handling Menu
3Configuration Menu
4Printing Menu
5I/O Menu
6Calibration Menu
7Resets Menu
272 Troubleshooting C7085-90921
Figure 7-12 4550 series menu map
1Information menu
2Paper handling menu
3Printing menu
4Configuration menu
5I/O menu
6Calibration menu
7Resets menu
8Quick Copy Jobs menu (only shown if a hard disk is installed)
9Private/Stored Jobs menu (only shown if a hard disk is installed)
Note Some menus only appear when the hard disk is installed.
123
4567
C7085-90921 Chapter 7 Troubleshooting 273
Information Menu
The Information Menu selections are used for changing and printing specific printer information.
Table 7-11 HP Color LaserJet 4500 Information Menu
Menu item Description
PRINT MENU MAP Prints the control panel menu map.
PRINT
CONFIGURATION
Prints the printer configuration page.
PRINT CONFIG
CONTINUOUS
Continuously prints the configuration page
until [Cancel Job] is pressed.
PRINT
FONT LIST
Prints the available PCL and PS (emulated
PostScript) font samples.
PRINT
LASERJET DEMO
Prints a demonstration page containing
five images (A4/LTR).
PRINT
LASERJET DEMO 2
Prints a duplexed (simplex if no duplexer
present) demo page on the size shown in
default size. (48 MB required for simplex,
64 MB for duplex).
PRINT ACCESSORIES Prints a page giving the accessory and
supplies part numbers (in English, French,
German, and Spanish).
PRINT COLOR GUIDE Prints a how to use color guide (A4/LTR).
SHOW EVENT LOG Prints a historical list of printer events.
REMAINING LIFE Displays the projected remaining life for the
transfer belt, fuser, and imaging drum.
Table 7-12 HP Color LaserJet 4550 Information Menu
Menu item Description
PRINT MENU MAP Prints the control panel menu map.
PRINT
CONFIGURATION
Prints the printer configuration page.
PRINT
FONT LIST
Prints the available PCL and PS (emulated PostScript) font
samples.
PRINT
FILE DIRECTORY
Prints the name and directory of files stored in the printer on
an optional hard disk or RAM memory module.
PRINT
EVENT LOG
Prints a historical list of printer events.
SHOW
EVENT LOG
Displays a historical list of printer events on the control
panel.
PRINT PAPER PATH
TEST
Prints a test of the paper path for the printer to make sure
there are no media jams.
PRINT USAGE PAGE Prints a count of all media sizes that have passed through
the printer. Also lists whether they were simplex, duplex,
monochrome, or color.
PRINT SUPPLIES
STATUS PAGE
Prints the estimated remaining life for the toner cartridges,
transfer belt, fuser, and imaging drum.
PRINT
LASERJET DEMO
Prints a demonstration page for the printer.
ACCESSORIES LIST Prints a list of optional accessories that have been installed
on the printer.
COLOR GUIDE Prints a one-page guide with hints on using color effectively.
274 Troubleshooting C7085-90921
Paper Handling Menu
The Paper Handling Menu allows you to configure input trays by size and type. This menu can also
be used to set the default media size and type.
Note The default mode for Tray 1 is TRAY 1 MODE=FIRST. In this mode, if media is loaded in Tray 1 and
no other tray is requested, the printer will pull media from Tray 1 regardless of the size and type of
media loaded in the tray. To configure Tray 1 by size or type, it must be configured as TRAY 1
MODE=CASSETTE.
*Denotes default setting
**A-4 is the default for printers sold in Asia
Table 7-13 HP Color LaserJet 4500 Paper Handling Menu
Menu item Values
TRAY 1 MODE FIRST*
CASSETTE
TRAY 1 SIZE
(appears only if Tray 1 mode is set to
TRAY 1 MODE=CASSETTE)
LETTER*/A4**
LEGAL
EXEC
JIS B5
A5
CUSTOM
B5
COM10
C5
DL
MONARC
TRAY 1 TYPE
(appears only if Tray 1 mode is set to
TRAY 1 MODE=CASSETTE)
PLAIN*
PREPRINTD
LTRHEAD
TRNSPRNCY
GLOSS
PREPUNCHD
LABELS
BOND
RECYCLED
COLOR
HEAVY
CARDSTOCK
TRAY 2 TYPE (same choices as TRAY 1 TYPE except
LABELS and CARDSTOCK)
TRAY 3 TYPE (same choices as TRAY 1 TYPE except
LABELS and CARDSTOCK)
A4/LETTER
OVERRIDE
NO*
YES
DEFAULT SIZE (same choices as TRAY 1 SIZE)
C7085-90921 Chapter 7 Troubleshooting 275
Table 7-14 HP Color LaserJet 4550 Paper Handling Menu
Menu item Values
TRAY 1 MODE FIRST*
CASSETTE
TRAY 1 SIZE
(appears only if Tray 1
mode is set to
TRAY 1
MODE=CASSETTE)
LETTER*/A4**
LEGAL
EXEC
JIS B5
A5
CUSTOM
B5
COM10
C5
DL
MONARC
TRAY 1 TYPE
(appears only if Tray 1
mode is set to
TRAY 1
MODE=CASSETTE)
PLAIN*
PREPRINTD
LTRHEAD
TRNSPRNCY
GLOSS
PREPUNCHD
LABELS
BOND
RECYCLED
COLOR
HEAVY
CARDSTOCK
TRAY 2 TYPE (same choices as TRAY 1 TYPE except LABELS and
CARDSTOCK)
TRAY 3 TYPE (same choices as TRAY 1 TYPE except LABELS and
CARDSTOCK)
MANUAL FEED ON
OFF
276 Troubleshooting C7085-90921
Configuration Menu
The Configuration Menu is used to set general printer default settings.
CAUTION Hewlett-Packard recommends that configuration settings only be changed by a system administrator.
Configuration settings seldom need to be changed.
*Denotes default setting
Table 7-15 HP Color LaserJet 4500 Configuration settings
Menu item Values Description
POWERSAVE OFF
1 MIN (used for
troubleshooting)
30 MIN
1 HR*
2 HRS
4 HRS
8 HRS
The length of time before the printer
goes into power-saving mode.
PERSONALITY AUTO*
PCL
PS
The personality (language) the
printer uses to process a print job.
CLEARABLE
WARNINGS
JOB*
ON
If ON, message appears until [Go] is
pressed. If JOB, message appears
until end of print job.
AUTO CONTINUE ON*
OFF
Determines whether the printer
continues printing when certain
errors occur. If ON, printer returns to
the READY state. If OFF, printer
remains offline until [Go] is pressed.
TONER LOW CONTINUE*
STOP
Determines whether the printer
continues or stops printing when a
TONER LOW condition is detected.
JAM RECOVERY OFF*
ON
Printer attempts to recover from
jams and reprints affected pages.
PRINT PS ERRORS OFF*
ON
Prints out an error page when
emulated PostScript errors occur.
C7085-90921 Chapter 7 Troubleshooting 277
*Denotes default setting
Table 7-16 HP Color LaserJet 4550 Configuration settings
Menu item Values Description
POWERSAVE OFF
1 MIN (used for
troubleshooting)
15 MIN
30 MIN*
1 HR*
2 HRS
4 HRS
The length of time before the printer goes into power-saving
mode.
CLEARABLE
WARNINGS
JOB*
ON
If ON, message appears until [Go] is pressed. If JOB,
message appears until end of print job.
AUTO CONTINUE ON*
OFF
Determines whether the printer continues printing when
certain errors occur. If ON, printer returns to the READY
state. If OFF, printer remains offline until [Go] is pressed.
JAM RECOVERY OFF*
ON
Printer attempts to recover from jams and reprints affected
pages.
PRINT PS ERRORS OFF*
ON
Prints out an error page when emulated PostScript errors
occur.
RAM DISK OFF*
ON
Determines if a RAM disk is installed and whether or not it is
activated.
RAM DISK SIZE= Displays the size (in MG or GB) of the activated RAM disk (if
installed).
QUICK COPY JOBS= Displays the number of Quick copy jobs saved in printer
memory.
HELD JOB TIMEOUT OFF*
ON
Sets the length of time the printer will save a held job in
memory prior to deleting it.
PERSONALITY AUTO*
PCL
PS
The personality (language) the printer uses to process a
print job.
278 Troubleshooting C7085-90921
Printing Menu
The Printing Menu is used to set default settings for a specific print job.
*Denotes default setting
1Only appears when the duplex unit is attached
2Only appears when DUPLEX is selected
3Only appears when a fixed space font is specified
4Only appears when a proportional space font is specified
Table 7-17 HP Color LaserJet 4500 Printing Menu settings
Menu Item Values Description
COPIES 1 to 999 (default:1) Number of copies.
ORIENTATION PORTRAIT*
LANDSCAPE
Determines the default
page orientation.
FORM LENGTH 5 to 128 lines
(default: 60)
Maximum lines on a page
before a formfeed occurs.
DUPLEX1OFF*
ON
Enables two-sided printing.
BINDING2LONG EDGE*
SHORT EDGE
Prints pages for specified
binding type.
PCL FONT SOURCE INTERNAL*
SOFT
SLOT n (n = 1,2,3)
Instructs the printer where
to look for PCL fonts.
PCL FONT NUMBER 0 to 999 (default: 0) Specifies a default PCL font
number.
PCL FONT PITCH30.44 to 99.99
(default: 10)
Specifies a default pitch for
PCL fonts.
PCL FONT
POINT SIZE44 to 999.75
(default: 12)
Specifies a default font size
for PCL fonts.
PCL SYMBOL SET PC-8 (default) Used to select an
appropriate symbol set.
COURIER REGULAR*
DARK
Note: Dark Courier was
used in older LaserJet
printers.
APPEND CR TO LF NO*
YES
Appends a carriage return
to each line feed character
in the data stream. (UNIX)
C7085-90921 Chapter 7 Troubleshooting 279
*Denotes default setting
1Only appears when a fixed space font is specified
2Only appears when a proportional space font is specified
Table 7-18 HP Color LaserJet 4550 Printing Menu settings
Menu Item Values Description
COPIES 1 to 999 (default:1) Number of copies.
UNIT OF MEASURE INCHES
MM
Set the unit of measurement.
X DIMENSION Determine the length of the
custom size media.
Y DIMENSION Determine the width of the
custom size media.
ORIENTATION PORTRAIT*
LANDSCAPE
Determines the default page
orientation.
PCL FONT SOURCE INTERNAL*
SOFT
SLOT n (n = 1,2,3)
Instructs the printer where to
look for PCL fonts.
PCL FONT NUMBER 0 to 999 (default: 0) Specifies a default PCL font
number.
PCL FONT PITCH10.44 to 99.99
(default: 10)
Specifies a default pitch for
PCL fonts.
PCL FONT
POINT SIZE24 to 999.75
(default: 12)
Specifies a default font size
for PCL fonts.
PCL SYMBOL SET PC-8 (default) Used to select an appropriate
symbol set.
WIDE A4 NO*
YES
Sets the printer to allow side-
A4 type media.
APPEND CR TO LF NO*
YES
Appends a carriage return to
each line feed character in
the data stream. (UNIX)
280 Troubleshooting C7085-90921
I/O Menu
The I/O Menu allows you to make changes to printer interface settings. The following table lists the
selections that appear for each item in this menu.
*Denotes default setting
1Only appears if I/O BUFFER is ON
EIO Menu
If an Enhanced Input Output (EIO) card (for example, an HP JetDirect Print Server) has been
installed in the printer, an additional menu is available. This additional menu provides a way to
configure the EIO accessory and to adjust network interface settings. For information about
HP JetDirect EIO menus, see the HP JetDirect Print Server Software Installation Guide. This guide
is included with the HP Color LaserJet 4500N and 4500DN printers and the 4550N, 4550DN and
4550HDN printers, and is also available through HP Direct. (See Appendix D in the online user
guide for ordering information.)
Table 7-19 HP Color LaserJet 4500 I/O Menu settings
Menu Item Values Description
I/O TIMEOUT 5 to 300 SECONDS
(default: 15)
Amount of time the printer
waits to receive data before
switching to another port.
I/O BUFFER AUTO*
OFF
ON
Allocates memory to I/O
ports.
I/O BUFFER SIZE1nnnnnnK
(default: 100K)
Amount of memory
allocated to the I/O ports.
PARALLEL HIGH
SPEED
YES*
NO
Allows faster parallel
communications supported
by newer computers.
PARALLEL
ADV FUNCTIONS
ON*
OFF
Turns bidirectional parallel
communication on and off.
Table 7-20 HP Color LaserJet 4550 I/O Menu settings
Menu Item Values Description
PARALLEL HIGH
SPEED
YES*
NO
Allows faster parallel
communications supported
by newer computers
C7085-90921 Chapter 7 Troubleshooting 281
Calibration Menu
This printer features automatic, internal calibration to produce optimum color for most print jobs. The
Calibration Menu provides fine-tuning for critical color-matching requirements.
For information about using this menu to set toner densities, see page 250.
CAUTION Calibrating toner densities changes the color balance of your printer by altering halftones. It affects all
print jobs. Notify your network administrator before performing this procedure.
Table 7-21 HP Color LaserJet 4500 Calibration Menu settings
Menu Item Values Description
PRINT
CALIBRATION PAGE
Prints out the color
calibration page.
CYAN
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing cyan toner
density.
MAGENTA
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing magenta toner
density.
YELLOW
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing yellow toner
density.
BLACK
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing black toner
density.
RESET DENSITY
VALUES
Resets density values back
to default settings. Press
[Select] to reset values.
Table 7-22 HP Color LaserJet 4550 Calibration Menu settings
Menu Item Values Description
PRINT
CALIBRATION PAGE
Prints out the color
calibration page.
CYAN
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing cyan toner
density.
MAGENTA
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing magenta toner
density.
YELLOW
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing yellow toner
density.
BLACK
DENSITY
-5 to +5
(default: 0)
Used for increasing or
decreasing black toner
density.
RESET DENSITY
VALUES
Resets density values back
to default settings. Press
[Select] to reset values.
282 Troubleshooting C7085-90921
Resets Menu
The Resets Menu is used for resetting the printer’s memory and for returning the printer to its
factory default settings. It is also used to clear maintenance messages following the replacement of
certain consumable items.
Table 7-23 HP Color LaserJet 4500 Resets Menu settings
Menu Item Description
RESET MEMORY Resets the printer to user-specified default settings.
RESTORE FACTORY
DEFAULTS
Resets the printer to factory default settings.
NEW TRANSFER KIT
SELECT IF DONE
Clears the maintenance message after the transfer kit
has been replaced.
NEW FUSER KIT
SELECT IF DONE
Clears the maintenance message after the fuser kit has
been replaced.
Table 7-24 HP Color LaserJet 4550 Resets Menu settings
Menu Item Description
NEW [COLOR]
CARTRIDGE
Resets the toner gauge for the printer and allows printing to
continue.
NEW TRANSFER KIT
SELECT IF DONE
Clears the maintenance message after the transfer kit has
been replaced.
NEW FUSER KIT
SELECT IF DONE
Clears the maintenance message after the fuser kit has
been replaced.
RESET MEMORY Resets the printer to user-specified default settings.
RESTORE FACTORY
SETTINGS
Resets the printer and control panel menus to factory
default settings.
POWERSAVE Allows PowerSave feature to be turned on or off.
C7085-90921 Chapter 7 Troubleshooting 283
Hard disk dependent menus
Quick Copy Jobs menu
This menu provides a list of the quick copy jobs stored on the printer hard disk. The user can print or
delete these jobs from the control panel.
Note If there are no quick copy jobs stored on the printer’s hard disk, this menu is not displayed on the
control panel.
Table 7-25 HP Color LaserJet 4550 Quick Copy Jobs menu
Menu Item Values Description
[JOBNAME] The name of the quick copy
job defined by the sender.
COPIES=1 1 to 999
DELETE
The number of additional
copies the user wants to
print.
284 Troubleshooting C7085-90921
Private/Stored Jobs menu
This menu provides a list of the private and stored jobs on the printer’s hard disk. The user can
print or delete these jobs from the control panel.
Note If there are no private or stored jobs on the printer’s hard disk, this menu is not displayed on the
control panel.
Table 7-26 HP Color LaserJet 4550 Private/Stored Jobs menu
Menu Item Values Description
[JOBNAME] The name of the job defined
by the sender stored on the
printer’s hard disk.
PIN: 0000 To print the job, the user must
enter the Personal
Identification Number (PIN)
that was assigned to the job
in the driver.
COPIES=1 1 to 999
DELETE
The number of copies the
user wants to print.
1-999: Prints the requested
number of copies of the job.
DELETE: Deletes the job
from the printer’s hard disk.
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Troubleshooting tools
Embedded Web server
The embedded Web server allows you to view printer and network status and to manage printing
functions from your PC instead of from the printer control panel. This service is designed for offices
using an IP network and a standard Web browser. Below are examples of what you can do using the
embedded Web server:
view printer control panel messages
determine the remaining life on all consumables
order consumables
view and change tray configurations
view and change the printer control panel menu configuration
view and print internal pages
receive notification of printer events
view and change network configuration
To use the embedded Web server, you must have an IP-based network and a Web browser. The
embedded Web server can be used with Microsoft Internet Explorer 4 or above, and with Netscape
Navigator 4 and above. IPX-based printer connections are not supported by the embedded Web
server.
To use the embedded Web server
1Open your Web browser.
2Type the IP address assigned to the printer into the Address or Location field.
The IP address for the printer is listed on the printer configuration page. For more information about
printing a Configuration Page, see Printer configuration page (page 287).
Embedded Web server page sets
The embedded Web server has three sets of internal Web pages for collecting information about the
printer and for changing configuration options. These sets are:
Home pages
Device pages
Networking pages
When the embedded Web server is active, each set of pages is listed on the browser screen. Click
on the set that you want to view, and the selection expands to display a list of frequently accessed
Web links.
Note Each page in the embedded Web server connects to online Help. For more information regarding a
particular page, click the Help button.
286 Troubleshooting C7085-90921
Home page set
The home pages of the embedded Web server are the informational pages for the printer. These
include:
Printer Status page
This page displays printer capabilities, control panel messages, and status lights that currently
appear on the printer control panel. From here, you can set the frequency at which the
embedded Web server will check the printer status. This page also displays consumable life
levels and the input tray configurations.
Configuration page
This page displays the printer configuration page. For more information about interpreting and
printing the configuration page, see page 287.
Supplies status page
This page displays the levels of the consumables for the printer. For more information about
interpreting and printing the supplies status page, see page 290.
Usage page
This page displays the amount of each media type that has been used by the printer. For more
information about interpreting and printing the usage page, see page 291.
Event Log page
This page displays the printer’s event log. For more information about interpreting and printing
the event log, see page 292.
Device Identification page
This page displays the name, asset number, network address, model number, and serial
number for this printer. To set the name and asset number, see the description of the Device
Identification page below.
Device page set
The device pages of the embedded Web server allow you to configure the printer from your PC.
The device pages can be password protected. Always consult with your network administrator
before changing the printer’s configuration.
Configure Printer page
Configure all printer settings from this page.
Alerts page
Input a list of recipients for electronic notification of various printer events.
E-Mail page
Configure the incoming and outgoing mail servers.
Security page
Set a password for the embedded Web server. Passwords and features configuration should
only be determined by the network administrator. If a password is set, users will require a
password for entry into the device sections of the embedded Web server.
Other Links page
Add or customize links to other websites. These links are displayed on the navigational bar
throughout the embedded Web server pages.
There are two permanent links, “Ask a question” where the user can get help with the printer,
and “Order Supplies” where you can order printer supplies. Order Supplies is only available
from the Device page set.
Language page
Determine the language in which to display the embedded Web server information.
Device Identification page
Name the printer and assign an asset number to it. Input the name and email address of the
primary point of contact for information about the printer. This page also shows the printer’s
network names, addresses, and printer model information.
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Networking page set
This set of pages allows the network administrator to configure the HP JetDirect card for the printer.
Refer to the online Help and to the HP JetDirect Print Server Administrator’s Guide for more
information.
WWW To download the HP JetDirect Print Server Administrator’s Guide, go to http://www.hp.com/support/
lj4550. When you connect, select Manuals.
Printer configuration page
Printing a printer configuration page can help you verify that the printer is configured properly. This
can be useful in troubleshooting printer problems.
To print a printer configuration page
1On the printer control panel, press [MENU] until INFORMATION MENU appears.
2Press [ITEM] until PRINT CONFIGURATION appears.
3Press [SELECT] to print the configuration page. The printer will return to the READY state.
Note If the printer is configured with EIO cards (for example, an HP JetDirect Print Server), an additional
configuration page will print that provides interface configuration information.
Interpreting the printer configuration page
The following sample illustrates a printer configuration page.
Figure 7-13 4500 series (left) and 4550 series (right) printer configuration page
1 Printer information—Lists the printer serial number, PCL/Emulated PostScript firmware
revision, total number of pages printed during the life of the printer, and total number of color
pages printed during the life of the printer.
2Event log—Lists the last five printer events, including printer jams, service errors, and other
printer conditions.
3 Installed personalities and options—Lists installed options such as EIO cards, DIMMs, duplex
printing accessory, and 500-sheet paper feeder.
4I/O menu—(Color LaserJet 4500 series only) Lists the current settings of the I/O menu items.
1
2
39
8
7
12
14
288 Troubleshooting C7085-90921
5 Configuration menu—(Color LaserJet 4500 series only) Lists the current settings of the
configuration menu items.
6 Printing menu—(Color LaserJet 4500 series only) Lists the current settings of the printing
menu items.
7Memory—Shows the total memory installed and the total memory available in the printer. Also
lists the memory allocation settings.
8Security—Shows whether the printer control panel is locked or unlocked. Also shows whether
the printer control panel password is enabled or disabled.
9 Paper trays—Lists the size and type of media currently configured for each input tray. Also lists
the current Tray 1 mode, A4/letter override setting, and default size setting.
10 Density settings—(Color LaserJet 4500 series only) Lists the current density settings.
11 Printing Menu—(Color LaserJet 4500 series only) Lists the current settings of the printing
menu items.
12 Color blocks—The color blocks verify color printing ability of the printer. The color blocks in
the middle of the page are primary colors, and the color blocks surrounding the page are
secondary colors. Each color is shown in 100-, 75-, 50-, and 25-percent fill.
13 Printer usage information—(4500 series only; 4550 series usage information is on the Usage
Page) Shows the number of pages printed for the following items:
Row 1: Paper size
000000 000000 000000 000000 000000
Custom Envelope Legal Executive/B5 Letter/A4
Row 2: Fuse modes
000000 000000 000000 000000 000000
Normal Heavy OHT Gloss Envelope
Row 3: Source tray
000000 000000 000000 000000
Tray 1 Tray 2 Tray 3 Duplex
Row 4: Language
000000 000000 000000
PCL pages PS pages XL pages
Row 5: Media types
000000 000000 000000 000000 000000 000000
Plain Pre-printed Letterhead Transparency Prepunched Labels
Row 6: Media types
000000 000000 000000 000000 000000 000000
Bond Recycled Color Card Gloss Heavy
C7085-90921 Chapter 7 Troubleshooting 289
14 Calibration density settings—On the bottom row of text, there are four separate blocks of
numbers. The first block is for cyan, second for magenta, third for yellow, and the last is for black.
Make sure the numbers are not near zero (if so, no calibration was done).
Note Do not print the configuration page until the printer is ready or calibration will not occur.
Note For rows one to three, the page count is incremented
after every ten pages. Row four is incremented after
every end of page. Rows one to four are counted
through the engine. Rows five and six are driver
requests.
The tray count is incremented based on the tray that is
selected by the firmware, not the tray that is selected
by the user.
Media size count is incremented based on the media
size that is selected by the user. Media type count is
incremented based on 1) the media type that is
selected by the user when the media is pulled from tray
1; and 2) the media type configured on the tray when
media is pulled from tray 2 or tray 3.
Fuse mode count is incremented twice for duplexed
sheets, once when the front side is fused and once
when the back side is fused.
Row 1: Paper size
290 Troubleshooting C7085-90921
Supplies status page
The supplies status page shows the remaining life for the following printer consumables and kits:
toner cartridges (all colors)
drum kit
transfer kit
fuser kit
It also lists useful printer information including the total number of pages printed (in monochrome
and in color), the printer serial number, and the part numbers for the supplies.
To print the supplies status page
1On the printer control panel, press MENU until INFORMATION MENU appears.
2Press ITEM until PRINT SUPPLIES STATUS PAGE appears.
3Press SELECT to print the supplies status page. After the process is completed, the printer will
return to the READY state.
Interpreting the supplies status page
The following sample illustrates a supplies status page.
Figure 7-14 Supplies status page
Print cartridge information
1Black Toner Gauge
2Cyan Toner Gauge
3Magenta Toner Gauge
4Yellow Toner Gauge
Other supplies information
5Imaging drum kit
6Transfer kit
7Fuser kit
Printer information
8Printer usage totals
C7085-90921 Chapter 7 Troubleshooting 291
Usage page
The usage page lists a page count for each size of media that has passed through the printer. This
page count includes the number of pages that were printed on one side, the number that were
printed on two sides (duplexed), and totals of the two printing methods for each media size. It also
lists the average percentage of page coverage for each toner color.
To print the usage page
1On the printer control panel, press MENU until INFORMATION MENU appears.
2Press ITEM until PRINT USAGE PAGE appears.
3Press SELECT to print the usage page. After the process is completed, the printer will return to
the READY state.
Interpreting the usage page
The following sample illustrates a usage page.
Figure 7-15 Usage page
1Usage totals (all media sizes)
2Black coverage
3Cyan coverage
4Yellow coverage
5Magenta coverage
1
2
3
4
292 Troubleshooting C7085-90921
Event log
Detailed service information is noted in the event log. The following is a list of the types of
messages logged in the event log:
jam errors
EIO errors
catastrophic errors
The last 50 errors are listed with the most recent error listed first. The event log can be viewed
either on the control panel display or it can be printed from the control panel.
To view the event log on the printer’s control panel
1Press [MENU] until INFORMATION MENU appears on the control panel display.
2Press [ITEM] until SHOW EVENT LOG appears on the display.
3Press [SELECT] to view the event log on the control panel display.
4Press [GO] to bring the printer back online.
To print the event log (4500 series)
1Access the printer’s service mode (see page 293).
2Press [ITEM] until PRINT CONFIGURATION appears.
3Press [SELECT] to print the configuration page. Up to 50 events will be printed on the
configuration page.
To print the event log (4550 series)
1On the printer control panel, press MENU until INFORMATION MENU displays.
2Press ITEM until PRINT EVENT LOG displays.
3Press SELECT to print the event log. After the process is completed, the printer will return to
the READY state.
Hard disk file directory page
Information about the optional 5 GB hard disk is listed on the Hard Disk File Directory page.
Figure 7-16 Hard disk file directory page
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Service mode
Service mode allows for the modification of page counts and certain registration values for the
printer. In the 4500 series, when the configuration page is printed while in service mode all event log
messages (up to 50 events) will be printed. In the 4550 series, the event log is printed from the
Information menu. If both the formatter and DC controller are replaced at the same time, service
mode will be utilized to execute the color plane registration sequence that ensures optimum print
quality.
Accessing the service mode
1Hold down [CANCEL JOB] and [SELECT] while turning the printer on until the display is blank and the
three LEDs are on.
2Press the right side of the [MENU +] key, and then press [SELECT].
SERVICE MODE will appear on the front panel briefly followed by two rows of asterisks. The printer will
go through its normal start-up cycle, and then display SERVICE MODE on the front panel again. Below
is a menu map showing what is available in service mode.
Figure 7-17 Service mode menu map
294 Troubleshooting C7085-90921
Printing the menu map in service mode
Printing the menu map while in service mode provides access to the Service Menu as well as other
control panel menus and their settings.
Figure 7-18 HP Color LaserJet 4500 series Service menu map
1Service Menu
2Information Menu
3Paper Handling Menu
4Configuration Menu
5Printing Menu
6I/O Menu
7Calibration Menu
C7085-90921 Chapter 7 Troubleshooting 295
Figure 7-19 HP Color LaserJet 4550 series Service menu map
1Information menu
2Paper Handling Menu
3Printing Menu
4Configuration Menu
5I/O Menu
6Calibration Menu
7Resets menu
8Quick Copy Jobs menu (only shown if a hard disk or RAM disk is installed)
9Private/Stored Jobs menu (only shown if a hard disk or RAM disk is installed)
Note Some menus only appear when the hard disk is installed.
1 2 3
4 5 6 7
296 Troubleshooting C7085-90921
Description of Service Menu items
The following menu items should be used by trained service personnel only. These items are used
to ensure the printer functions properly.
Serial number
The serial number displayed on the front panel should match the serial number tag located on the
rear of the printer, as this is the serial number printed on the configuration page.
Setting the serial number:
1Press the [ITEM] key until SERIAL NUMBER = (number) appears.
2Press the [VALUE +/–] key to change the character with the cursor under it.
3Press [SELECT] to save the character and move the cursor to the next slot.
4Repeat steps 2 and 3 until all the characters match the label on the back of the printer.
Transfer maintenance count
There are two methods to track the life of the intermediate transfer belt (ITB):
The life lever on the ITB actually indicates when the ITB has reached its end of life.
The transfer maintenance count (printed on the configuration page) shows the percent of life
used. This number is not critical to printer operation, but it provides a way for customers to
monitor consumable life. The transfer maintenance count is set to zero when the life message
for the ITB is reset. If you replace the ITB before the end of life message appears, you also
need to set this value to zero.
Setting transfer maintenance count
1Press the [ITEM] key until transfer maintenance count appears.
2Press the [VALUE +/–] key to set the number.
3Press [SELECT] to save.
4Repeat steps 2 and 3 to change the other numbers if required.
Fuser maintenance count
The fuser maintenance count functions the same way as other HP LaserJet printers. This count is
the actual life of the fusing unit and is used to indicate its end of life. If the fuser is replaced before
the end of life message appears, the fuser count must be reset to zero. An actual end of life
condition will have a reset to clear the end of life message and set the fuser count to zero.
Setting fuser maintenance count:
1Press the [ITEM] key until FUSER MAINTENANCE COUNT appears.
2Press the [VALUE +/–] key to set the number.
3Press [SELECT] to save.
4Repeat steps 2 and 3 to change the other numbers if required.
Color page count
Color page count is used to track the number of pages printed with any color other than black.
Although this count is not critical, there might be customers who use it to track the number of color
documents printed. If the number needs to be reentered, select a number which is as close as
possible to the original. An earlier configuration page is a great source if one can be found.
Setting color page count:
1Press the [ITEM] key until COLOR PAGE COUNT appears.
C7085-90921 Chapter 7 Troubleshooting 297
2Press the [VALUE +/–] key to set the number.
3Press [SELECT] to save.
4Repeat steps 2 and 3 to change the other numbers if required.
Total page count
Total page count tracks the total number of pages printed. As with the color page count, the number
is not critical but can be useful for customers.
Setting total page count:
1Press the [ITEM] key until TOTAL PAGE COUNT appears.
2Press the [- VALUE +] key to set the number.
3Press [SELECT] to save.
4Repeat steps 2 and 3 to change the other numbers if required.
Clear event log
Clear event log (event log empty) does exactly what it says. There can be times when it is necessary
to clear the event log to allow the tracking of an issue. To clear the event log press the [SELECT] key.
Once the event log is cleared it will read event log empty.
The next items in the list deal with color plane registration along with top and left margin settings for
the different trays. Please refer to the registration page section for an explanation of these settings
and how to set them.
Paper tray size functional test
Use the status/test feature of the service mode to check the function of the paper tray size switches.
See the status/test address table in this chapter for information about this test.
Registration page
Note You must set the registration values if both the formatter and DC controller are replaced at the same
time or if the formatter had been previously installed in another printer. If the DC controller is replaced
by itself, these values are copied from the formatter to the DC controller. If a new formatter is replaced,
or if an NVRAM initialization is performed (see NVRAM initialization on page 307), these values are
loaded onto the formatter from the DC controller.
Registration offset—As the ITB ages, the Color Plane Registration might need to be checked. See
the instructions below for printing a registration page.
Registration offset has also occurred when a printer has been damaged and the scanner itself was
offset.
To print a registration page:
1Scroll through the Service Menu until PRINT REGISTRATION PAGE appears.
2Select which paper tray to pull paper from (only when setting left side margins will the tray
actually matter).
3Press [SELECT] to print the registration page.
In the center of the page are horizontal (Scan) and vertical (Process) sets of bars for cyan, magenta,
and yellow. Each bar is made up of a series of lines, with black being used as the base for setting the
correct registration values for the three other colors. Along the top and left sides of the page are lines
with numbers which are used for top and left side margins. The tray from which paper was pulled is
listed on the bottom of the page.
To set registration numbers
298 Troubleshooting C7085-90921
On each of the color bars in the process section are bolded numbers that indicate the current
number set on the control panel. These bolded numbers will always be in the middle of the bars. To
set the correct value for each of the colors, look at the lines within the bar and find the grouping that
has the color line directly on top of the black line (it will have more white space). Print at least five
registration pages to see if the new settings are correct.
Hint Using a magnifying glass to look at the lines will help in selecting the best number.
Figure 7-20 Registration page
Note Hewlett-Packard strongly recommends that the registration values be selected on the basis
of averaging five consecutive samples.
Setting the registration number:
1Press the [ITEM] key to select the appropriate color (cyan, magenta, or yellow) at its registration
number.
2Press the [VALUE +/–] key to change the registration number to the one identified.
3Press the [SELECT] key to enter the value.
Setting margin numbers
The top margin number is not tray-dependent like the left side margin. Simply print the registration
page from whichever tray has paper. Using a ruler, measure from the top edge of the paper to the
series of lines. Find the line that is 13 mm (0.5 in) away from the paper’s edge.
C7085-90921 Chapter 7 Troubleshooting 299
Setting the top margin registration value
1Press the [ITEM] key to scroll through the service menu until top margin appears.
2Press the [MENU +/–] key until the number to be entered appears.
3Press the [SELECT] key to enter the number.
Print another registration page and the number just entered will align with the arrow and be printed in
bold.
The left side margin setting is tray dependent. Tray 1 has its own number while trays 2 and 3 are
combined. The procedure is the same as the top margin with one exception. The page must be
printed from the tray that will be adjusted.
Printing from tray 1
1Press the [ITEM] key until PRINT REGISTRATION PAGE TRAY =1 (default) appears.
2Press the [SELECT] key.
3Measure from the left side of the paper to the lines and find the line which is 13 mm (0.5 inches)
from the edge.
If the number for the line is different than the current number:
1Press the [ITEM] key until TRAY 1 LEFT MARGIN = # appears.
2Press the [VALUE] key to change the number to the number required.
3Press the [SELECT] key.
Printing from tray 2 and 3
1Press the [ITEM] key until PRINT REGISTRATION PAGE TRAY = 2 or 3 appears.
2Press the [SELECT] key.
3Measure from the left side of the paper to the lines and find the line which is 13mm (0.5 inches)
from the edge.
If the number for the line is different than the current number:
1Press the [ITEM] key until TRAY 2 AND 3 LEFT MARGIN = # appears.
2Press the [VALUE] key to change the number to the number required.
3Press the [SELECT] key.
300 Troubleshooting C7085-90921
Diagnostics mode
This section provides an overview of the diagnostic tools incorporated into the HP Color LaserJet
4500/4500N/4500DN printer and the HP Color LaserJet 4550/4550N/4550DN/4550HDN printer.
CAUTION Take caution when performing printer diagnostics to avoid risk of injury. Only trained service
personnel should access the diagnostics mode with the skins removed.
There are two diagnostic sections built into the firmware, one for the formatter and the other for the
engine. Each section contains different tests that allow the service technician to verify printer
functionality. While in diagnostics mode there are no error messages associated with these tests.
Therefore, determination of the problem will rely on the technician’s skill. To exit diagnostics mode,
turn off the printer.
Note In the 4550 series, you can abort a test run by pressing the [CANCEL JOB] key and holding it down
until the display shows the menu again. In some cases, it will take several seconds. To cancel the
NVRAM test while it is running, press the [CANCEL JOB] key and hold it down until the display show
the menu again. NVRAM is put back in its original form, and an error is logged in the Fault log.
When the Attention LED is on, then there ahs been an error in the test. Press the [MENU] key to get
to the Fault log menu, the [ITEM] key to see the different log messages, and the [-VALUE+] key to scroll
the message back and forth.
Entering diagnostics mode
1To open diagnostics mode, hold down the left side of the [ITEM] key and turn on the printer.
Formatter diagnostics
Formatter diagnostics are designed to be used by qualified service personnel to thoroughly test the
functionality of the formatter. If all the tests pass, the formatter is working correctly and it can be
assumed that the problem resides elsewhere. Listed below are descriptions of the formatter tests
available.
Table 7-27 Formatter diagnostics
Test Description
REPEAT If set to YES, the tests will run continuously until
interrupted. In the 4550 series only, [CANCEL JOB] will
abort the test.
ON FAULT The following will occur for each setting:
BREAK - the test will stop when a failure occurs.
PAUSE - the test will stop for a short period of time then
resume with the remaining tests.
CONT - the tests will continue even when a failure occurs.
ROM CRC 4500 series only. Tests the firmware ROM for correct
functionality.
DRAM Tests the on-board RAM and the DIMMs.
SRAM 1 Tests the SRAM inside the ASIC.
SRAM 2 Tests the SRAM physically mounted on the formatter.
C7085-90921 Chapter 7 Troubleshooting 301
NVRAM
CAUTION Do not interrupt the NVRAM test. Doing
so will cause the printer to lose all
NVRAM values.
In almost all cases, this test should not be run. Tests the
formatter NVRAM. This test takes 15-18 minutes to run
and should only be used when NVRAM values are being
lost.
In the 4550 series only, [CANCEL JOB] will abort the test.
Do not turn off the printer or corruption of the NVRAM
could result; if the NVRAM test must be aborted, use the
[CANCEL JOB] key.
EXECUTE
TESTS
Runs the selected tests.
Table 7-27 Formatter diagnostics
Test Description
302 Troubleshooting C7085-90921
Engine diagnostics
Engine diagnostics access portions of the printer’s internal diagnostics that occur when the printer
is turned on. These diagnostics are available as tools to help isolate problems that are not reported
by the firmware. As mentioned previously, no error message will appear if there is a problem in the
section being tested. A good understanding of how the printer operates is required to use the
engine diagnostics successfully.
To have a better view of the areas being exercised, remove the left side cover and the ITB drawer.
Defeat the two ITB drawer switches (SW 1 and SW 4) located on the left-side of the drawer cavity.
Now you can run the diagnostics and watch the assemblies as they are operated.
Listed below in (Table 7-28) are the diagnostics available and a brief description of what each
diagnostic will do. A detailed explanation for each diagnostic can be found under its own heading
later in this document.
Paper path test
1Press the [ITEM] key until you see ENGINE DIAGS PAPER PATH TEST.
2Press the [SELECT] key to activate the test. While the test is running you will see ENGINE DIAGS
E1:PAPERPATH displayed in the front panel.
The test takes approximately 15 seconds to run.
Components exercised by the paper path test include the fusing motor (M1), paper path pick-up
motor (M2), and associated gears and assemblies. The paper pick up roller for tray 2 can be
activated by manually activating the paper pick solenoid (SL2). This test will not pick up paper and
move it through the paper path. To test this function, simply run a configuration page. For multiple
pages, select continuous configuration page in the control panel.
Table 7-28 Engine diagnostics
Menu Item Selectable
Value Description
CONTINUOUS N (default)
Y
Selected test will run once.
Selected test will run in a continuous
loop. In the 4550 series only, [CANCEL
JOB] will abort the test.
PAPER PATH
TEST
Turns on the motors that control the
paper path section of the printer. In the
4550 series only, [CANCEL JOB] will
abort the test.
DEVELOPER
TEST
Rotates the carousel and the
developers. In the 4550 series only,
[CANCEL JOB] will abort the test.
DRUM TEST Turns on the drum drive motor that
drives the drum and ITB. In the 4550
series only, [CANCEL JOB] will abort the
test.
PATH SENSORS Displays the state for each of the paper
path sensors and switches. In the 4550
series only, this test will continue
running until the [CANCEL JOB] key is
pressed.
DOOR SENSORS Displays the state for each of the door
and drawer switches. In the 4550
series only, this test will continue
running until the [CANCEL JOB] key is
pressed.
C7085-90921 Chapter 7 Troubleshooting 303
The paper path test allows the service technician to verify the operation of components within the
paper path. When the test is initiated both the M1 and M2 are activated. You will see the ITB lift cams
rotate once and the ITB drive gear turn briefly. The remaining portion of the test simply allows both
the M1and M2 to run, thus exercising the gears and rollers associated with them.
Note If an error occurs during the paper path test, the message PATH_1PAPER PATH TEST FAILED appears.
Developer test
The developer test rotates the carousel stopping at each toner cartridge and rotating the developer
sleeve. For the best view of the carousel and the toner cartridge sleeves, remove the drum cartridge.
The drum drawer must be closed before the test can run.
1Press the [ITEM] key until ENGINE DIAGS DEVELOPER TEST appears.
2Press the [SELECT] key to run the test. The front panel will display ENGINE DIAGS E2:DEVELOPER
while the test is running. Watch the carousel and make sure the toner cartridge developer sleeve
rotates. The sequence will be black followed by a pause, then magenta, cyan, and finally yellow.
The test will last for approximately 35 seconds. While the developer test is running you will see the
drum turn if it is installed, as well as the drive gear for the ITB.
Drum test
The drum test exercises the drum drive mechanism. Also, the fuser motor is turned on to allow the lift
cams for the ITB to be rotated into the ITB up position.
1Press the [ITEM] key until ENGINE DIAGS DRUM TEST appears.
2Press the [SELECT] key to run the test. The front panel will display ENGINE DIAGS E3:DRUM while
the test is running.
Watch to see if the ITB lift cams turn and if both the drum drive gear and the ITB drive gear are
rotating.
Path sensors test
The path sensors test allows the paper path sensors and switches to be tested for correct operation.
Table 7-29 shows the correlation between the identifier on the front panel and the sensor or switch it
represents.
Table 7-29 Paper path sensors and switches
Identifier Name Description
APS8 Tray 2 paper detect sensor
BPS3 Tray 1 last sheet of media pulled sensor
CPS4 Tray 1 paper detect sensor
DSW801 Tray 2 paper size switch 2
ESW802 Tray 2 paper size switch 1
FSW803 Tray 2 paper size switch 0
GPS3001 Optional Tray 3 paper detect sensor
HSW3001 Optional Tray 3 paper size switch 2
ISW3002 Optional Tray 3 paper size switch 1
JSW3003 Optional Tray 3 paper size switch 0
KPS10 Carousel position sensor
304 Troubleshooting C7085-90921
1Press the [ITEM] key until ENGINE DIAGS PATH SENSORS appears on the front panel.
2Press the [SELECT] key to activate the test. The front panel will display A through N with a binary
value below it.
When running this test, make sure the ITB drawer is installed and trays 2 and 3 are removed. In this
state the default value on the front panel should be: 0X111111110010, where the x can be either a
0 or 1. If there is any other value, then there is a possible problem. Identify the sensor or switch in
the table above and test to see if the value changes. Cassette paper size settings for each tray are
described in Table 7-30.
* These values are the same for Tray 3.
Door sensor test
The door sensor test allows service personnel to open and close doors on the printer while
watching the sensor status on the front panel. Switches 4 and 5 are in series with each other which
causes the value to toggle under identifier A.
Once the door sensor test is initiated, the front panel displays the status for each sensor listed in
Table 7-31. As a door is opened and closed the state of the sensor changes the indicator values on
the front panel.
LPS11 ITB photo sensor
MN/A 500-sheet feeder: 1=installed, 0=uninstalled
NPS9 Top output tray full sensor
Table 7-30 Paper size settings
Paper Size Tray 2 Switches
(DEF) Tray 3 Switches
(HIJ)
A4 000 000
B5 001 001
Custom (A5) 010 011*
Custom (B5 ISO) 011 011*
Letter 100 100
Executive 101 101
Legal 110 110
No tray installed 111 111
Table 7-31 Sensor status
Identifier Name Description
ASW4 and SW5 Front and rear door
switches
BSW1 * ITB drawer switch
CSW2 * Toner cartridge door *
DSW3 * Drum drawer switch *
EDrum detect Detect if a drum cartridge is
installed
Table 7-29 Paper path sensors and switches (continued)
Identifier Name Description
C7085-90921 Chapter 7 Troubleshooting 305
* Activates (A) as well when opened.
1Press the [ITEM] key until ENGINE DIAGS DOOR SENSORS appears on the front panel.
2Press the [SELECT] key to activate the test.
The front panel will display A through F with a binary value below it. All the doors and drawers should
be closed. In this state the display will show all 0’s. Open the doors and drawers one at a time to
verify correct functionality. If operating correctly, the 0 will change to a 1. If a 1 appears with all doors
and drawers closed, there is a defective switch or connection.
FFuser Detects if fuser is installed.
Changes state if not
detected or removed when
rear door is opened and
closed.
Table 7-31 Sensor status
Identifier Name Description
306 Troubleshooting C7085-90921
Engine test
The printer has one test pattern (vertical lines). When an image defect appears, a test print can be
made to identify the problem. The test print can be made by pressing the test print switch located
on the right side of the printer (Figure 7-21). A test pattern can be printed by pressing the test print
switch once after the photosensitive drum has stopped and the printer has entered the standby
mode. If the switch is held down, the test pattern is printed continuously. The switch can be used
when paper is loaded in any tray other than tray 1.
The engine test does the following:
Verifies that the print engine is functioning correctly (the formatter PCB is completely bypassed
during an engine test).
Isolates printer problems.
Checks and adjusts registration.
Prints from tray 2 or 3 only, not from tray 1.
Can be activated with the formatter PCB removed.
Note For the printer to perform an engine test, tray 2 must be installed and loaded with paper, and the
toner cartridge must be installed in the printer.
Figure 7-21 Location of the engine test button
Engine test button
C7085-90921 Chapter 7 Troubleshooting 307
NVRAM initialization
NVRAM initialization should always be executed immediately after replacing the firmware or the
formatter board. This procedure aligns the firmware with the formatter. Not performing NVRAM
initialization could result in deterioration of print quality. Before initializing NVRAM, be sure to gather
and write down the information listed below, if possible.
Total page count and color page count. Print a configuration page to obtain both page counts
and the serial number.
Percentage of life remaining for both the transfer kit and the fuser kit
a. From SERVICE MODE on the printer display panel, press [MENU].
b. Go to SERVICE MENU and press [ITEM].
c. Use the [-VALUE +] keys to go to TRANSFER MAINT COUNT=XXXXXXX and write down the exact
numbers shown.
d. Go to FUSER MAINT COUNT=XXXXXXX and write down the exact numbers shown.
Serial number.
To initialize NVRAM
1Turn on the printer while holding down both the [CANCEL JOB] and [SELECT] keys until all the LED
lights are on, then release the keys.
2Press [CANCEL JOB].
3Press [SELECT].
After replacing the firmware or the formatter board, the following settings are changed or lost. If you
do not wish to accept the new values, use Service Mode to enter the previous settings that you wrote
down before initializing.
Total page count and total color page count (the counter is reset to 0)
Transfer kit percentage of life remaining (gauge is reset to 100 percent)
Fuser kit percentage of life remaining (gauge is reset to 100 percent)
Printer serial number
308 Troubleshooting C7085-90921
Diagrams
This section contains wiring diagrams and photos of all internal printer components.
Figure 7-22 Sensor locations
PS3001
PS3104
PS3105
PS3103
PS3101
PS3102
PS10
PS9 PS11
PS6
PS7 PS13
PS1
PS8
PS2 PS4
PS3
PS301
PS14
PS12 PS5
CTLS
Table 7-32 Sensor function and locations
Name Function
PS1 ITB unit life sensor
PS2 Registration paper sensor
PS3 Last paper sensor
PS4 Multipurpose tray paper sensor
PS5 ITB home position sensor
PS6 Fusing unit pressure release sensor
PS7 Delivery paper sensor
PS8 Cassette paper sensor
PS9 Face-down tray paper full sensor
PS10 Carousel home position sensor
PS11 Toner cartridge press sensor
PS12 Toner level sensor
C7085-90921 Chapter 7 Troubleshooting 309
Figure 7-23 Printer solenoids and clutches
PS13 Waste toner sensor
PS14 Density sensor
PS301 OHT sensor (multipurpose tray PCB)
PS3001 Paper feed detection sensor
PS3101 Reversing unit paper sensor
PS3102 Face-up sensor
PS3103 Reversing unit stationary paper sensor
PS3104 Duplex pick-up paper sensor
PS3105 Side registration home position sensor
CTLS Continuous toner level sensor
Table 7-32 Sensor function and locations (continued)
Name Function
SL2 SL1
CL2 CL1
CL3
CL4
Table 7-33 Solenoid and clutch functions and locations
Name Function
SL1 Multipurpose tray pick-up solenoid
SL2 Paper pick-up solenoid
CL1 Registration clutch
CL2 ITB unit separation clutch
CL3 ITB cleaning roller separation clutch
CL4 Secondary transfer roller separation clutch
310 Troubleshooting C7085-90921
Figure 7-24 Printer motors and fans
Figure 7-25 Miscellaneous sensors and clutches
M1 M2
FM2
FM1
M5
M4
M3
FM3
Table 7-34 Printer motors and fans
Name Code Description
Motors M1 Fusing motor
M2 Pick-up motor
M3 Carousel motor (carousel drive unit)
M4 Drum motor (drum drive unit)
M5 Toner cartridge motor
Fan Motors FM1 Large fan
FM2 Small fan
FM3 Fan (upper front cover fan)
PS2 PS301
PS1
CL1
C7085-90921 Chapter 7 Troubleshooting 311
Figure 7-26 Intermediate transfer belt sensors
Table 7-35 Miscellaneous sensors and clutches
Name Description
PS2 Registration sensor
PS301 Overhead transparency sensor
PS1 Intermediate transfer belt life sensor
CL1 Registration clutch (on outside drawer wall)
Cleaning Roller 1
2
Table 7-36 Intermediate transfer belt sensors
Name Description
1 Intermediate transfer belt (end of life lever)
2 Intermediate transfer belt (home position sensor) (PS5)
312 Troubleshooting C7085-90921
Figure 7-27 Miscellaneous sensors (with tray 1 front cover removed)
Figure 7-28 PS6 and PS7 sensor location
PS3 PS4
Table 7-37 PS3 and PS4 description
Name Description
PS3 Tray 1 last page sensor
PS4 Tray 1 paper sensor
PS7 PS6
Table 7-38 PS6 and PS7 description
Name Description
PS6 Fusing assembly pressure sensor
PS7 Paper exit sensor (access through the opening)
C7085-90921 Chapter 7 Troubleshooting 313
Figure 7-29 Miscellaneous switches
Figure 7-30 Miscellaneous switches and sensors
SW801, SW802, SW803
Table 7-39 Switch description
Name Description
SW801, SW802,
SW803 Paper tray size switches (power supply and high-voltage
power supplies removed)
SW2
SW5
PS13
Table 7-40 SW2, SW5, and PS13 description
Name Description
SW2 Top cover (toner door) switch
SW5 Top cover/rear door +24V interrupt switch
PS13 Waste toner full sensor
314 Troubleshooting C7085-90921
Figure 7-31 PS14 sensor location
Figure 7-32 Miscellaneous parts
PS14
Table 7-41 Density sensor location
Name Description
PS14 Density sensor
11
12
13
14
6
9
1
8
7
5
4
3
2
10
Table 7-42 Miscellaneous parts
Location Name
1Drum ground connector
2Drum drawer closed switch (SW3)
3Front drawers drum/ITB +24V interrupt switch (SW4)
4ITB drawer closed switch (inside chassis wall) (SW1)
C7085-90921 Chapter 7 Troubleshooting 315
Figure 7-33 Imaging drum connector
5Tray 2 pickup solenoid (behind chassis wall) (SL2)
6Secondary transfer roller clutch (CL4)
7Pickup motor (M2)
8ITB contact/separation clutch (behind lower gear) (CL2)
9Fusing motor (M1)
10 Paper feed PCB
11 Cleaning roller cam clutch (CL3)
12 Toner level sensor (emitter receiver) (PS12)
13 Carousel “home position” sensor (PS10)
14 Rear left (small) cooling fan connector
Table 7-42 Miscellaneous parts
Location Name
1
2
3
Table 7-43 Imaging drum connector
Location Name
1Fan (FM3)
2Imaging drum connector
3FM3 cooling fan connector (drawer to chassis)
316 Troubleshooting C7085-90921
Figure 7-34 Rear door interlock switch defeat
Figure 7-35 Right rear fan
Press to defeat
C7085-90921 Chapter 7 Troubleshooting 317
Figure 7-36 Fuse (F1) and CB101
Figure 7-37 Fusing assembly
1
2
Table 7-44 Fuse F1 and CB101 location
Location Description
1Fuse F1
2Circuit breaker CB101
1
1A
1B
2A
2B
3A
3B
4A
4B
2
34
Table 7-45 110-volt fusing assembly
Location Description
Pin 1 Frame ground
Pins 2 to 4 6.3 ohms ± 1 ohm
318 Troubleshooting C7085-90921
Figure 7-38 DC controller PCB connectors
Pins 3 to 2 3.1 ohms ± 1 ohm
Pins 4 to 3 3.1 ohms ± 1 ohm
1A to 2A 310 K to 430 K ohm at (room temperature)
1B to 2B 310 K to 430 K ohm at (room temperature)
3B to 4B Short 110-volt unit
Table 7-45 110-volt fusing assembly
Location Description
Rear of printer
Front of printer
C7085-90921 Chapter 7 Troubleshooting 319
Note: Some locations will vary slightly depending on the version of the printer.
Figure 7-39 Location of connectors
320 Troubleshooting C7085-90921
Note: Some locations will vary slightly depending on the version of the printer.
Figure 7-40 Location of duplexer and 500-sheet paper feeder connectors
C7085-90921 Chapter 7 Troubleshooting 321
Figure 7-41 500-sheet feeder wiring diagram
322 Troubleshooting C7085-90921
C7085-90921 Chapter 8 Parts and diagrams 323
8Parts and diagrams
Chapter contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Ordering parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Consumables, accessories, and supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Common fasteners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
Illustrations and parts lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Alphabetical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Numerical parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
324 Parts and diagrams C7085-90921
Introduction
The figures in this chapter show the major subassemblies in the printer and their component parts.
A table (materials list) follows each exploded assembly diagram. Each table lists the reference
designator (item number), the associated part number, quantity, and description of each part.
Note When looking for a part number, pay careful attention to the voltage listed in the description column
to ensure that the part number selected is for the correct printer model.
C7085-90921 Chapter 8 Parts and diagrams 325
Ordering parts
All standard part numbers are stocked and can be ordered from Commercial Support Services
Organization-Americas (CSSO-A) or Commercial Support Services Organization-Europe (CSSO-E).
For information about contacting CSSO-A or CSSO-E, see page 41.
Note Parts that have no reference designator or part number are not field replaceable and cannot be ordered.
Consumables, accessories, and supplies
The items listed in Table 8-1 are available through your local authorized HP dealer. To find a dealer
near you (or if your local dealer is temporarily out of stock), call the HP Customer Information Center
at (800) 752-0900.
Note See page 327 for documentation part numbers.
Consumable parts and accessories are available directly from Hewlett-Packard at the following
numbers:
U.S.: (800) 538-8787
Canada: (800) 387-3154, (Toronto) (416) 671-8383
United Kingdom: 0734-441212
Contact your local HP Parts Coordinator for other local phone numbers.
Table 8-1 Consumables, accessories, and supplies
Product number Part number Description
Cables
C2946A 3 m (9 ft) parallel cable (IEEE-1284 compliant)
with a 25-pin DB male to a (IEEE-1284C) male
“C” connector
92215N LocalTalk cable kit
92215S DIN-8 printer cable (for Macintosh computers)
Consumable items
C4195A R94-4001-410CN Drum kit
C4196A R96-5009-000CN Transfer kit
C4197A R96-5007-000CN Fuser kit (110V)
C4198A R96-5008-000CN Fuser kit (220V)
5090-3379 Toner cloths
Localized font DIMMS
5062-4667 Greek (1 MB)
5062-4668 Hebrew (1 MB)
5062-4669 Cyrillic (1 MB)
5062-4670 Arabic (1 MB)
C4292A (CAS) Traditional Chinese (8 MB)
C4293A (CAS) Simplified Chinese (8 MB)
YS-90210 Japanese (8 MB)
326 Parts and diagrams C7085-90921
Media
C2934A HP Color LaserJet Transparencies (letter)
C2936A HP Color LaserJet Transparencies (A4)
C4179A HP Color LaserJet Soft Gloss Paper (letter)
C4179B HP Color LaserJet Soft Gloss Paper (A4)
100-pin Memory (DIMMS)
C4140A C4140-67901 4 MB (HP Color LaserJet 4500)
C4141A C4041-67901 8 MB (HP Color LaserJet 4500)
C4142A C4042-67901 16 MB (HP Color LaserJet 4500)
C4143A C4043-67901 32 MB (HP Color LaserJet 4500)
C3913A C3913-67901 64 MB (HP Color LaserJet 4500)
168-pin Memory (DIMMS)
C7848A C7848-60001 64 MB (HP Color LaserJet 4550)
C7850A C7850-60001 128 MB (HP Color LaserJet 4550)
Network Connectivity
J3110A J3110-69001 HP JetDirect 600N for ethernet (10Base-T
[RJ-45])
J3111A J3111-69001 HP JetDirect 600N for ethernet (10Base-T
[RJ-45] and 10Base-2 [BNC]) and LocalTalk
(DIN-8)
J3112A J3112-69001 HP JetDirect 600N for Token Ring (DB9, RJ-45)
J3113A J3113-69001 HP JetDirect 600N for Fast Ethernet (10/100
Base-TX [RJ-45])
J4169A J4169-69001 HP JetDirect 610N for Fast Ethernet (10/100
Base-TX [RJ-45])
Options
C4082A C4082-67901 500-sheet input tray
C4083A C4083-67901 Duplex unit (two-sided printing)
C4235A HP Color LaserJet 4500 cabinet
J6054A 5 GB Hard Disk (4550 series only)
C4103A Fast Infrared Pod (4550 series only)
C4286A Flash firmware DIMM (4550 series only)
Panel overlays
C4084-40001 English
C4084-40005 German
C4084-40003 French
C4084-40006 Spanish
C4084-40004 Italian
C4084-40015 Korean
C4084-40018 Simplified Chinese
C4084-40014 Traditional Chinese
Table 8-1 Consumables, accessories, and supplies (continued)
Product number Part number Description
C7085-90921 Chapter 8 Parts and diagrams 327
Note The only difference between the toner cartridges listed above is that the Europe-only toner cartridges
have different languages on the instruction sheet inside the box.
C4084-40011 Swedish
C4084-40007 Dutch
C4084-40009 Finnish
C4084-40016 Russian
C4084-40008 Danish
C4084-40010 Norwegian
C4084-40012 Portuguese
C4084-40017 Czech
C4084-40013 Polish
C4084-40020 Japanese
Reference Materials
5963-7863 HP LaserJet Printer Family Print Media Guide
5961-0976 HP PCL/PJL Reference Set
5969-6818 HP JetDirect Print Server Administrator’s Guide
5969-3412 HP JetDirect Print Server JetAdmin Setup Guide
Toner supplies
C4191A R94-4005-410CN Black
C4192A R94-4004-410CN Cyan
C4193A R94-4003-410CN Magenta
C4194A R94-4002-410CN Yellow
C4191A R94-4005-510CN Black (Europe only)
C4192A R94-4004-510CN Cyan (Europe only)
C4193A R94-4003-510CN Magenta (Europe only)
C4194A R94-4002-510CN Yellow (Europe only)
Table 8-1 Consumables, accessories, and supplies (continued)
Product number Part number Description
328 Parts and diagrams C7085-90921
Common fasteners
Table 8-2 Types of screws
Illustration Description Size Uses
Screw, machine
w/washer M3X6
M3X10
M3X12
M3X14
To hold plastic
to metal,
(ex. the skins)
Screw, self
tapping M4X8
M4X10 To hold plastic
to plastic,
(ex. control
panel)
Screw, trus
head M3X4
M3X6
M3X8
Sheet metal to
sheet metal,
(ex. formatter
pan)
Retaining Ring
(e-type) To hold gears
into place
C7085-90921 Chapter 8 Parts and diagrams 329
Illustrations and parts lists
The following illustrations and parts tables list the field replaceable units (FRU) for this printer. At the
end of this chapter are two tables of all of the parts shown in this chapter: Table 8-18 lists the parts in
alphabetical order, and table 8-19 lists the parts in numerical order by part number. Both tables list
the appropriate figure in this chapter where the part can be found.
Determining the printer version
Two versions of the HP Color LaserJet 4500 series printer are available. To accurately perform
removal and replacement procedures or determine the correct part for reordering, you will need to
know the version of the printer that is being serviced. To identify the printer, check the serial number,
which is located at the rear of the printer. All printers will have US or JP in the first two positions of the
serial number (e.g., USBB123456). Newer versions of the HP Color LaserJet 4500 printer will have
an “H” or higher letter in the third position (e.g., USHB123456). If the letter in the third position in the
serial number is “B”, “C”,”D”, or “F”, then you have an older version of the HP Color LaserJet 4500
printer. The HP Color LaserJet 4550 series printer is equivalent to the newer version of the HP Color
LaserJet 4500 series printer, unless otherwise noted, although it does have some different service
parts from the 4500 series.
330 Parts and diagrams C7085-90921
Figure 8-1 Assembly location diagram (1 of 2)
1Fuser assembly
2Intermediate Transfer Belt assembly
3Paper path and trans port
4Feeder assembly
5Transfer assembly
54
2
1
3
C7085-90921 Chapter 8 Parts and diagrams 331
Figure 8-2 Assembly location diagram (2 of 2)
1Cartridge carousel and housing assembly
2Carousel drive assembly
3Toner cartridge carousel assembly
1
2
3
332 Parts and diagrams C7085-90921
Figure 8-3 PCB locations
5
1
4
2
6
3
8
7
9
C7085-90921 Chapter 8 Parts and diagrams 333
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-3 PCB assembly
Ref. Description Qty. Parts for 4500
series s/n xxG...
and below
Parts for 4500
series s/n xxH...
and above
Parts for HP Color
LaserJet 4550
1 Developing PCB 1 RG5-3811-000CN RG5-5180-000CN RG5-5180-000CN
2 DC controller PCB 1 RG5-3809-000CN RG5-5254-000CN RG5-5254-000CN
3 Interconnect PCB 1 RG5-3808-000CN RG5-3808-000CN RG5-3808-000CN
4 Paper size sensor PCB 1 RG5-3816-000CN RG5-3816-000CN RG5-3816-000CN
5 Paper feed PCB assembly 1 RG5-3810-000CN RG5-3810-000CN RG5-3810-000CN
6 Formatter PCB 1 C4084-69001* C4084-69001* C4227-69001*
7 Firmware DIMM 1 C4084-60004 C4084-60004 C9130-60001
8 I/O card 1 C4081-60001 C4081-60001 C4207-60001
9 Toner level sensor PCB 1 N/A N/A RG5-5247-000CN
*These parts require exchange
334 Parts and diagrams C7085-90921
Figure 8-4 External covers, panels, etc.
1
2
34
5
6
8
9
10
11
12
7
C7085-90921 Chapter 8 Parts and diagrams 335
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Note Early CLJ4500 printers (serial numbers xxGxxxxxxx and below) have two versions of the drum drawer
cover and the upper (drum) drawer assembly (Figure 8-7, item 6 and Figure 8-13, item 1). If the drum
drawer cover requires replacement, first determine whether you have the original version of the drum
drawer by locating a bar code label with a part number of RG5-3315 on the inside of the drum drawer
cover, just to the right of the fan cover. If you have the original version of the drum drawer, order kit
part number RG5-5230-000CN to obtain the newer version of the drum drawer assembly, drum drawer
cover, plus additional hardware required to complete the update. If the newer version of the drum
drawer is already installed, simply order the replacement drum drawer cover (RG5-5232-000CN).
Table 8-4 Printer cover and door
Ref. Description Qty. Parts for 4500
series s/n xxG...
and below
Parts for 4500
series s/n xxH...
and above
Parts for 4550
series
1 Cover, right side 1 RB2-1203-000CN RB2-1203-000CN RB2-1203-000CN
2 Cover, connector 1 RB2-1224-000CN RB2-1224-000CN RB2-1224-000CN
3 Cover, right front 1 RG5-3310-000CN RG5-3310-000CN RG5-3310-000CN
4 Cable, control panel 1 RG5-3802-000CN RG5-5195-000CN RG5-5195-000CN
5 Control panel assembly 1 RG5-5200-000CN RG5-5200-000CN RG5-5200-000CN
6 Cover, ITB drawer 1 RG5-3320-000CN RG5-3320-000CN RG5-3320-000CN
7 Tray, extension 1 RB2-1215-000CN RB2-1215-000CN RB2-1215-000CN
8 Cover, drum drawer 1 RG5-5232-000CN** RG5-5152-000CN RG5-5152-000CN
9 Cover, left side 1 RG5-3313-000CN RG5-5151-000CN RG5-5151-000CN
10 Cover, lower rear 1 RB2-1206-000CN RB2-1206-000CN RB2-1206-000CN
11 Door, rear access 1 RG5-3325-040CN RG5-3325-040CN RG5-3325-040CN
12 Cover, rear 1 RB2-1205-000CN RB2-1205-000CN RB2-1205-000CN
**Refer to note, below.
336 Parts and diagrams C7085-90921
Figure 8-5 Top cover assembly
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-5 Top cover components
Ref. Description Qty. Parts for 4500
series s/n xxG...
and below
Parts for 4500
series s/n xxH...
and above
Parts for 4550
series
1 Cover, top 1 RG5-3300-000CN RG5-5150-000CN RG5-5150-000CN
2 Cover, toner access 1 RF5-2076-000CN RF5-3137-000CN RF5-3137-000CN
1
2
C7085-90921 Chapter 8 Parts and diagrams 337
Figure 8-6 Internal components (1 of 3)
3
2
9
10
13
14
17
15
5
1
6
4
8
7
16
12
11
18
Table 8-6 Internal components (1 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Cable, fan 1 RG5-3887-000CN N/A N/A
2 Cable, developer 1 RG5-3783-000CN RG5-5187-000CN RG5-5187-000CN
3 Power supply, 110V 1 RH3-2219-000CN RH3-2219-000CN RH3-2219-000CN
3 Power supply, 220V 1 RH3-2220-000CN RH3-2220-000CN RH3-2220-000CN
4 High-voltage power supply 1 RG5-3285-000CN RG5-5165-000CN RG5-5165-000CN
5 Strap, cover support 1 RB2-1556-000CN RB2-1556-000CN RB2-1556-000CN
6 ITB assembly 1 RG5-5173-060CN RG5-5173-060CN RG5-5173-060CN
7 ITB drawer assembly 1 RG5-5120-100CN RG5-5120-100CN RG5-5120-100CN
8 Handle, ITB drawer 1 RB2-1361-000CN RB2-1361-000CN RB2-1361-000CN
9 Filter, air (small) 1 RB2-1283-000CN RB2-1283-000CN RB2-1283-000CN
10 Fan, small 1 RH7-1407-000CN RH7-1407-000CN RH7-1407-000CN
11 Fuser, 110V 1 RG5-5154-050CN
C4084-69002* RG5-5154-050CN
C4084-69002* RG5-5154-050CN
C4084-69002*
338 Parts and diagrams C7085-90921
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
11 Fuser, 220V 1 RG5-5155-050CN
C4084-69003* RG5-5155-050CN
C4084-69003* RG5-5155-050CN
C4084-69003*
12 Kit, Fuser Deflector 1 C4084-67906 C4084-67906 C4084-67906
13 Drum bushing assembly 1 RG5-5169-000CN RG5-5169-000CN RG5-5169-000CN
14 Rod, delivery 1 RB2-1284-000CN RB2-1284-000CN RB2-1284-000CN
15 Spring, tension 1 RS5-2754-000CN RS5-2754-000CN RS5-2754-000CN
16 Face-down delivery assembly 1 RG5-5135-000CN RG5-5135-000CN RG5-5135-000CN
17 Filter, air (large) 1 RB2-1282-000CN RB2-1282-000CN RB2-1282-000CN
18 Flapper guide assembly 1 RG5-5251-000CN RG5-5251-000CN RG5-5251-000CN
*These parts require exchange
Table 8-6 Internal components (1 of 3) (continued)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
C7085-90921 Chapter 8 Parts and diagrams 339
Figure 8-7 Internal components (2 of 3)
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-7 Internal components (2 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Cable, video interface 1 RH2-5335-000CN RH2-5335-000CN RH2-5335-000CN
2 Interconnect PCB 1 RG5-3808-000CN RG5-3808-000CN RG5-3808-000CN
3 Guide, cable 1 RB2-1277-000CN RB2-1277-000CN RB2-1277-000CN
4 Cable, main 1 RG5-3781-000CN RG5-5186-000CN RG5-5186-000CN
5 Roller, transfer 1 RF5-2112-000CN RF5-2112-000CN RF5-2112-000CN
6 Drum drawer assembly 1 RG5-5230-000CN RG5-5142-050CN RG5-5142-050CN
7 Drum drive assembly 1 RG5-5206-000CN RG5-5206-000CN RG5-5206-000CN
1
4
3
5
7
6
7
2
340 Parts and diagrams C7085-90921
Figure 8-8 Internal components (3 of 3)
1
2
12
13
11
10
9
4
5
6
8
14
3
-A
14 -B
7(SW3)
C7085-90921 Chapter 8 Parts and diagrams 341
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-8 Internal components (3 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Guide, upper drum drawer
cable 1 RB2-1457-000CN (included in 14B) (included in 14B)
2 Sensor, waste toner
(PS13) 1 RG5-3292-000CN RG5-3292-000CN RG5-3292-000CN
3 DC controller PCB 1 RG5-3809-000CN RG5-5254-000CN RG5-5254-000CN
4 Cable, fan 1 RG5-4650-000CN RG5-4650-000CN RG5-4650-000CN
5 Cover, cable 1 RB2-1180-000CN RB2-1180-000CN RB2-1180-000CN
6 Bushing, ITB left 1 RB2-1158-000CN RB2-5185-000CN RB2-5185-000CN
7 Microswitch 1 WC2-5330-000CN WC2-5330-000CN WC2-5330-000CN
8 Drawer switch assembly 1 RG5-3296-030CN RG5-3296-030CN RG5-3296-030CN
9 Laser/scanner assembly 1 RG5-5175-000CN RG5-5175-000CN RG5-5175-000CN
10 Cable, laser 1 RG5-3782-000CN RG5-3782-000CN RG5-3782-000CN
11 Cable, laser (flat) 1 RH2-5400-000CN RH2-5400-000CN RH2-5400-000CN
12 Carousel brake assembly 1 RG5-3309-000CN RG5-5163-000CN RG5-5163-000CN
13 Guide, cable, lower 1 RB2-1456-000CN RB2-1456-000CN RB2-1456-000CN
14A/B Door switch assembly 1 RG5-5170-000CN RG5-5170-000CN RG5-5170-000CN
342 Parts and diagrams C7085-90921
Figure 8-9 Developing carousel assembly
3
4
2
1
7
8
9
10
5
11
6
12
13
14
15
16
17
C7085-90921 Chapter 8 Parts and diagrams 343
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-9 Developing carousel assembly
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1Fan, large 1 RH7-1346-000CN RH7-1435-000CN RH7-1435-000CN
2Spacer 1 RS5-6210-000CN RS5-6210-000CN RS5-6210-000CN
3Bearing, carousel 1 XG9-0361-000CN XG9-0361-000CN XG9-0361-000CN
4Gear, 125T 1 RS6-0176-000CN RS6-0176-000CN RS6-0176-000CN
5Developing PCB 1 RG5-3811-000CN RG5-5180-000CN RG5-5180-000CN
6Carousel drive assembly 1 RG5-5209-000CN RG5-5209-000CN RG5-5209-000CN
7Cable, fusing connector 1 RG5-3886-000CN RG5-3886-000CN RG5-3886-000CN
8Cable, rotary 1 RG5-3795-000CN RG5-3795-000CN RG5-3795-000CN
9Sensor (PS12), toner level 1 RG5-3355-000CN RG5-3355-000CN RG5-3355-000CN
10 Sensor (PS10), carousel
position 1 WG8-5362-000CN WG8-5362-000CN WG8-5362-000CN
11 Carousel assembly 1 RG5-5249-000CN RG5-5249-000CN RG5-5249-000CN
12 Spring, toner flap 2 RS5-2739-000CN RS5-2739-000CN RS5-2739-000CN
13 Cap, toner flap 2 RB2-0964-000CN N/A N/A
14 Kit, carousel flap 1 C4084-67907 C4084-67909 C4084-67909
15 Toner level sensing PCB 1 N/A N/A RG5-5247-000CN
16 Toner level sensing cable 1 N/A N/A RG5-5444-000CN
17 Grounding spring 1 RB2-0981-000CN RB2-0981-000CN RB2-0981-000CN
344 Parts and diagrams C7085-90921
Figure 8-10 Paper pick-up assembly (1 of 3)
1
2
5
4
3
6
7
C7085-90921 Chapter 8 Parts and diagrams 345
Table 8-10 Paper pick-up assembly (1 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Cable, ITB switch 1 RG5-4651-000CN RG5-4651-000CN RG5-4651-000CN
2 Microswitch, ITB 1 WC2-5330-000CN WC2-5330-000CN WC2-5330-000CN
3 Sensor (PS7), delivery paper FH7-7313-000CN FH7-7313-000CN FH7-7313-000CN
4 Sensor (PS6), fusing unit
pressure release 1 WG8-5309-000CN WG8-5309-000CN WG8-5309-000CN
5 Feeder assembly 1 RG5-3226-000CN RG5-5117-000CN RG5-5117-000CN
6 ITB drawer connector 1 VS1-6174-014CN VS1-6174-014CN VS1-6174-014CN
7 ITB cable 1 RG5-3786-000CN RG5-3786-000CN RG5-3786-000CN
346 Parts and diagrams C7085-90921
Figure 8-11 Paper pick-up assembly (2 of 3)
1
2
3
4
5
6
7
8
9
11
10
13
14
12
18
19
16
15 17
20
21
22
23
24
25
26 27
28
29
30
31
33
32
34
35
Table 8-11 Paper pick-up assembly (2 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Gear, 17T 2 RS6-0158-000CN RS6-0158-000CN RS6-0158-000CN
2 Gear, 18T/14T 1 RS6-0157-000CN RS6-0157-000CN RS6-0157-000CN
3 Gear, 53T/46T 1 RS6-0156-000CN RS6-0156-000CN RS6-0156-000CN
4 Gear, 17T 1 RS6-0158-000CN RS6-0158-000CN RS6-0158-000CN
5 Roller 1 RF5-2092-000CN RF5-2092-000CN RF5-2092-000CN
6 Gear, 18T 1 RS6-0140-000CN RS6-0140-000CN RS6-0140-000CN
7 Gear, 19T 1 RS6-0141-000CN RS6-0141-000CN RS6-0141-000CN
8 Solenoid, Tray 2 feed (SL2) 1 RG5-3245-000CN RG5-5119-000CN RG5-5119-000CN
9 Gear, 27T 1 RS6-0135-000CN RS6-0135-000CN RS6-0135-000CN
10 Gear, 27T 1 RS6-0135-000CN RS6-0135-000CN RS6-0135-000CN
11 Gear, 30T/16T 1 RS6-0134-000CN RS6-0134-000CN RS6-0134-000CN
12 Bushing 2 RS5-1293-000CN RS5-1293-000CN RS5-1293-000CN
C7085-90921 Chapter 8 Parts and diagrams 347
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
13 Gear, 31T 1 RS6-0136-000CN RS6-0136-000CN RS6-0136-000CN
14 Motor (M2), pick-up 1 RH7-1343-000CN RH7-1343-000CN RH7-1343-000CN
15 Gear, 47T 1 RS6-0147-000CN RS6-0147-000CN RS6-0147-000CN
16 Gear, 24T/37T 1 RS6-0163-000CN RS6-0163-000CN RS6-0163-000CN
17 Gear, 35T 1 RS6-0132-000CN RS6-0132-000CN RS6-0132-000CN
18 Gear, 20T 1 RS6-0138-000CN RS6-0138-000CN RS6-0138-000CN
19 Gear, 37T/14T 1 RS6-0133-000CN RS6-0133-000CN RS6-0133-000CN
20 Gear, 34T/15T 1 RS6-0144-000CN RS6-0144-000CN RS6-0144-000CN
21 Gear, 29T/17T 1 RS6-0145-000CN RS6-0145-000CN RS6-0145-000CN
22 Gear assembly, 18T/52T 1 RF5-2161-000CN RF5-2161-000CN RF5-2161-000CN
23 Gear, 52T 1 RS6-0146-000CN RS6-0146-000CN RS6-0146-000CN
24 Motor (M1), fusing assembly 1 RG5-3227-000CN RG5-3227-000CN RG5-3227-000CN
25 Gear, 26T 1 RS6-0149-000CN RS6-0149-000CN RS6-0149-000CN
26 Gear, 37T 1 RS6-0143-000CN RS6-0143-000CN RS6-0143-000CN
27 Sensor, paper size 1 RG5-3234-000CN RG5-3234-000CN RG5-3234-000CN
28 Cable, paper feed 1 RG5-3785-000CN RG5-3785-000CN RG5-3785-000CN
29 Gear, 29T 1 RS6-0150-000CN RS6-0150-000CN RS6-0150-000CN
30 Gear, 29T 1 RS6-0150-000CN RS6-0150-000CN RS6-0150-000CN
31 Clutch (CL2), electromagnetic 1 RH7-5176-000CN RH7-5176-000CN RH7-5176-000CN
32 Sensor (PS8), cassette paper 1 WG8-5309-000CN WG8-5309-000CN WG8-5309-000CN
33 Spring, Tray 2 pickup tension 1 RS5-2794-000CN RS5-2794-000CN RS5-2794-000CN
34 Cone 1 RS5-1341-000CN RS5-1341-000CN RS5-1341-000CN
35 Metal tab, tray 2 1 RB2-0593-000CN RB2-0593-000CN RB2-0593-000CN
Table 8-11 Paper pick-up assembly (2 of 3) (continued)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
348 Parts and diagrams C7085-90921
Figure 8-12 Paper pick-up assembly (3 of 3)
1
2
3
4
5
7
8
9
10
12 11
13
14
15
17
16
18
19
20
21
22
23
25
24
26
27
6
28
29
30
30
31
33
32
Table 8-12 Paper pick-up assembly (3 of 3)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Cable, fusing/option 1 RG5-3787-000CN RG5-3787-000CN RG5-3787-000CN
2 Lever, sensor 1 RB2-0576-000CN RB2-0576-000CN RB2-0576-000CN
3 Clutch, one-way 1 RB2-0572-000CN RB2-0572-000CN RB2-0572-000CN
4 Gear, 18T 1 RS6-0139-000CN RS6-0139-000CN RS6-0139-000CN
5 Roller, paper pick 4 RB1-8865-000CN RB1-8865-000CN RB1-8865-000CN
6 Shaft, paper pick 1 RB2-0545-000CN RB2-0545-000CN RB2-0545-000CN
7 Transfer cam assembly 1 RG5-3240-000CN RG5-5118-000CN RG5-5118-000CN
8 Gear, 26T/18T 1 RS6-0137-000CN RS6-0137-000CN RS6-0137-000CN
9 Gear assembly 1 RG5-3228-000CN RG5-3228-000CN RG5-3228-000CN
10 Gear, 53T 1 RS6-0155-000CN RS6-0155-000CN RS6-0155-000CN
11 Gear, 39T/31T 1 RS6-0154-000CN RS6-0154-000CN RS6-0154-000CN
12 Gear, 49T 1 RS6-0153-000CN RS6-0153-000CN RS6-0153-000CN
13 Gear, 18T 1 RS6-0139-000CN RS6-0139-000CN RS6-0139-000CN
C7085-90921 Chapter 8 Parts and diagrams 349
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
14 Clutch (CL4), electromagnetic 1 RH7-5180-000CN RH7-5180-000CN RH7-5180-000CN
15 Gear, 16T 1 RS6-0151-000CN RS6-0151-000CN RS6-0151-000CN
16 Clutch (CL3), electromagnetic 1 RH7-5178-000CN RH7-5178-000CN RH7-5178-000CN
17 Gear, 29T 1 RS6-0152-000CN RS6-0152-000CN RS6-0152-000CN
18 Paper feed PCB assembly 1 RG5-3810-000CN RG5-3810-000CN RG5-3810-000CN
19 ICL cam assembly 1 RG5-3242-000CN RG5-3242-000CN RG5-3242-000CN
20 Clutch, one-way 1 RB2-0561-000CN RB2-0561-000CN RB2-0561-000CN
21 ITB cam assembly 1 RG5-3241-000CN RG5-3241-000CN RG5-3241-000CN
22 Clutch, one-way 1 RB2-0561-000CN RB2-0561-000CN RB2-0561-000CN
23 Rowel swing assembly 1 RG5-4696-000CN RG5-4696-000CN RG5-4696-000CN
24 Spring tension 1 RS5-2800-000CN RS5-2800-000CN RS5-2800-000CN
25 Link rowel 1 RB2-0614-000CN RB2-0614-000CN RB2-0614-000CN
26 Transfer assembly, secondary 1 RG5-3235-000CN RG5-5115-040CN RG5-5115-040CN
27 Plate support 1 RF5-3124-000CN (included in #26) (included in #26)
28 Gear, 26T 1 RS6-0159-000CN RS6-0159-000CN RS6-0159-000CN
29 Plate, left 1 RF5-2094-000CN RF5-2094-000CN RF5-2094-000CN
30 Cover, plate 2 RB2-1572-000CN RB2-1572-000CN RB2-1572-000CN
31 Plate, right 1 RF5-2095-000CN RF5-2095-000CN RF5-2095-000CN
32 Spring 1 RS5-2799-000CN RS5-2799-000CN RS5-2799-000CN
33 D roller assembly 1 RG5-3225-040CN RG5-3225-040CN RG5-3225-040CN
Table 8-12 Paper pick-up assembly (3 of 3) (continued)
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
350 Parts and diagrams C7085-90921
Figure 8-13 Upper drawer assembly
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
1
2
3
4
5
Table 8-13 Upper drawer assembly
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Drum drawer assembly 1 RG5-5230-000CN RG5-5142-050CN RG5-5142-050CN
2 Sensor (PS14), density 1 RG5-3281-000CN RG5-5149-000CN RG5-5149-000CN
3 Cover, connector 1 RB2-0916-000CN RB2-0916-000CN RB2-0916-000CN
4 Connector assembly 1 RG5-5146-000CN Rg5-5146-000CN RG5-5146-000CN
5 Bushing, drum drawer 1 RB2-1130-000CN RB2-1130-000CN RB2-1130-000CN
C7085-90921 Chapter 8 Parts and diagrams 351
Figure 8-14 MP tray paper pick-up assembly
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
2
1
3
4
Table 8-14 MP tray paper pick-up assembly
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Roller 1 RB2-0717-000CN RB2-0717-000CN RB2-0717-000CN
2 Roller 1 RB2-0744-000CN RB2-0744-000CN RB2-0744-000CN
3 Sensor (PS3) assembly, last
paper 1 RG5-5130-020CN RG5-5130-020CN RG5-5130-020CN
4 Sensor (PS4) assembly, multi-
purpose tray paper 1 RG5-5129-000CN RG5-5129-000CN RG5-5129-000CN
352 Parts and diagrams C7085-90921
Figure 8-15 250-sheet cassette
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
1
2
3
4
5
6
8
7
8
Table 8-15 250-sheet cassette
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Cassette, 250-sheet 1 RG5-3400-210CN RG5-3400-210CN RG5-3400-210CN
2 Cover, roller 1 RB1-9001-000CN RB1-9001-000CN RB1-9001-000CN
3 Limiter, torque 1 RB1-8974-000CN RB1-8974-000CN RB1-8974-000CN
4 Roller, separation 1 RF5-1885-000CN RF5-1885-000CN RF5-1885-000CN
5 Indicator, paper level 1 RB1-9009-020CN RB1-9009-020CN RB1-9009-020CN
6 Arm, lifter, left 1 RB1-9012-000CN RB1-9012-000CN RB1-9012-000CN
7 Arm, lifter, right 1 RB1-9013-000CN RB1-9013-000CN RB1-9013-000CN
8 Spring, torsion 2 RB1-9016-000CN RB1-9016-000CN RB1-9016-000CN
C7085-90921 Chapter 8 Parts and diagrams 353
Figure 8-16 500-sheet paper feeder
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
1
2
Table 8-16 500-sheet paper feeder
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 500-sheet paper feeder 1 C4082-67901 C4082-67901 C4082-67901
2 500-sheet paper cassette 1 RG5-3900-000CN RG5-3900-000CN RG5-3900-000CN
Roller, separation 1 RF5-1885-000CN RF5-1885-000CN RF5-1885-000CN
354 Parts and diagrams C7085-90921
Figure 8-17 Duplex unit
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329.
1
2
Table 8-17 Duplex unit
Ref. Description Qty. Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for 4550
series
1 Duplex unit 1 C4083-67901 C4083-67901 C4083-67901
2 Duplexing feeder assembly 1 RG5-4055-000CN RG5-4055-000CN RG5-4055-000CN
C7085-90921 Chapter 8 Parts and diagrams 355
Alphabetical parts list
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-18 Alphabetical parts list
Description Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for HP
Color LaserJet
4550 printer
Figure Reference
500-sheet paper cassette RG5-3900-000CN RG5-3900-000CN RG5-3900-000CN 8-18 2
500-sheet paper feeder C4082-67901 C4082-67901 C4082-67901 8-18 1
Arm, lifter, left RB1-9012-000CN RB1-9012-000CN RB1-9012-000CN 8-17 6
Arm, lifter, right RB1-9013-000CN RB1-9013-000CN RB1-9013-000CN 8-17 7
Bearing, carousel XG9-0361-000CN XG9-0361-000CN XG9-0361-000CN 8-11 3
Bushing, drum drawer RB2-1130-000CN RB2-1130-000CN RB2-1130-000CN 8-13 5
Bushing, ITB, left RB2-1158-000CN RB2-5185-000CN RB2-5185-000CN 8-10 6
Bushing RS5-1293-000CN RS5-1293-000CN RS5-1293-000CN 8-13 12
Cable, fusing connector RG5-3886-000CN RG5-3886-000CN RG5-3886-000CN 8-11 7
Cable, control panel RG5-3802-000CN RG5-5195-000CN RG5-5195-000CN 8-6 4
Cable, developer RG5-3783-000CN RG5-5187-000CN RG5-5187-000CN 8-8 2
Cable, fan RG5-3887-000CN N/A N/A 8-8 1
Cable, fan RG5-4650-000CN RG5-4650-000CN RG5-4650-000CN 8-10 4
Cable, fusing/option RG5-3787-000CN RG5-3787-000CN RG5-3787-000CN 8-14 1
Cable, ITB RG5-3786-000CN RG5-3786-000CN RG5-3786-000CN 8-10 7
Cable, ITB switch RG5-4651-000CN RG5-4651-000CN RG5-4651-000CN 8-12 1
Cable, laser RG5-3782-000CN RG5-3782-000CN RG5-3782-000CN 8-10 10
Cable, laser (flat) RH2-5334-000CN RH2-5334-000CN RH2-5334-000CN 8-10 11
Cable, main RG5-3781-000CN RG5-5186-000CN RG5-5186-000CN 8-9 4
Cable, paper feed RG5-3785-000CN RG5-3785-000CN RG5-3785-000CN 8-13 28
Cable, rotary RG5-3795-000CN RG5-3795-000CN RG5-3795-000CN 8-11 8
Cable, toner level sensor N/A N/A RG5-5247-000CN 8-11 16
Cable, video interface RH2-5335-000CN RH2-5335-000CN RH2-5335-000CN 8-9 1
Cap, toner flap RB2-0964-000CN N/A N/A 8-11 13
Carousel assembly RG5-5249-000CN RG5-5249-000CN RG5-5249-000CN 8-11 11
Carousel brake assembly RG5-3309-000CN RG5-5163-000CN RG5-5163-000CN 8-10 12
Carousel drive assembly RG5-5209-000CN RG5-5209-000CN RG5-5209-000CN 8-11 6
Cassette, 250-sheet RG5-3400-210CN RG5-3400-210CN RG5-3400-210CN 8-17 1
Clutch (CL2),
electromagnetic RH7-5176-000CN RH7-5176-000CN RH7-5176-000CN 8-13 31
Clutch (CL3),
electromagnetic RH7-5178-000CN RH7-5178-000CN RH7-5178-000CN 8-14 16
Clutch (CL4),
electromagnetic RH7-5180-000CN RH7-5180-000CN RH7-5180-000CN 8-14 14
Clutch, one-way RB2-0572-000CN RB2-0572-000CN RB2-0572-000CN 8-14 3
Clutch, one-way RB2-0561-000CN RB2-0561-000CN RB2-0561-000CN 8-14 20
Clutch, one-way RB2-0561-000CN RB2-0561-000CN RB2-0561-000CN 8-14 22
Cone RS5-1341-000CN RS5-1341-OOOCN RS5-1341-OOOCN 8-13 34
Connector RF5-2152-000CN RF5-2152-000CN RF5-2152-000CN 8-15 4
Continuous toner level
sensor PCB N/A N/A RG5-5247-000CN 8-9 15
Control panel assembly RG5-3345-000CN RG5-3345-000CN RG5-3345-000CN 8-6 5
Cover, cable RB2-1180-000CN RB2-1180-000CN RB2-1180-000CN 8-10 5
Cover, connector RB2-1224-000CN RB2-1224-000CN RB2-1224-000CN 8-6 2
356 Parts and diagrams C7085-90921
Cover, connector RB2-0916-000CN RB2-0916-000CN RB2-0916-000CN 8-15 3
Cover, drum drawer RG5-3315-000CN RG5-5152-000CN RG5-5152-000CN 8-6 8
Cover, ITB drawer RG5-3320-000CN RG5-3320-000CN RG5-3320-000CN 8-6 6
Cover, left side RG5-3313-000CN RG5-5151-000CN RG5-5151-000CN 8-6 9
Cover, lower rear RB2-1206-000CN RB2-1206-000CN RB2-1206-000CN 8-6 10
Cover, plate RB2-1572-000CN RB2-1572-000CN RB2-1572-000CN 8-14 30
Cover, rear RB2-1205-000CN RB2-1205-000CN RB2-1205-000CN 8-6 12
Cover, right front RG5-3310-000CN RG5-3310-000CN RG5-3310-000CN 8-6 3
Cover, right side RB2-1203-000CN RB2-1203-000CN RB2-1203-000CN 8-6 1
Cover, roller RB1-9001-000CN RB1-9001-000CN RB1-9001-000CN 8-17 2
Cover, toner access RF5-2076-000CN RF5-3137-000CN RF5-3137-000CN 8-7 2
Cover, top RG5-3300-000CN RG5-5150-000CN RG5-5150-000CN 8-7 1
DC controller PCB RG5-3809-000CN RG5-5254-000CN RG5-5254-000CN 8-5 2
DC controller PCB RG5-3809-000CN RG5-5254-000CN RG5-5254-000CN 8-10 3
Developing PCB RG5-3811-000CN RG5-5180-000CN RG5-5180-000CN 8-5 1
Developing PCB RG5-3811-000CN RG5-5180-000CN RG5-5180-000CN 8-11 5
Door switch assembly RG5-5170-000CN RG5-5170-000CN RG5-5170-000CN 8-10 14A/B
Door, rear access RG5-3325-040CN RG5-3325-040CN RG5-3325-040CN 8-6 11
Drawer switch assembly RG5-3296-040CN RG5-3296-030CN RG5-3296-030CN 8-10 8
Drum bushing assembly RG5-3319-000CN RG5-3319-000CN RG5-3319-000CN 8-8 13
Drum drawer assembly RG5-5230-000CN RG5-5142-000CN RG5-5142-000CN 8-9 6
Drum drawer assembly RG5-5230-000CN RG5-5142-000CN RG5-5142-000CN 8-15 1
Drum drive assembly RG5-3170-000CN RG5-3170-000CN RG5-3170-000CN 8-9 7
Duplex unit C4083-67901 C4083-67901 C4083-67901 8-19 1
Duplexing feeder
assembly RG5-4055-000CN RG5-4055-000CN RG5-4055-000CN 8-19 2
Face-down delivery
assembly RG5-5135-000CN RG5-5135-000CN RG5-5135-000CN 8-8 16
Fan, large RH7-1346-000CN RH7-1435-000CN RH7-1435-000CN 8-11 1
Fan, small RH7-1407-000CN RH7-1407-000CN RH7-1407-000CN 8-8 10
Feeder assembly RG5-3226-000CN RG5-5117-000CN RG5-5117-000CN 8-12 5
Filter, air (large) RB2-1282-000CN RB2-1282-000CN RB2-1282-000CN 8-8 17
Filter, air (small) RB2-1283-000CN RB2-1283-000CN RB2-1283-000CN 8-8 9
Firmware DIMM C4084-60004 C4084-60004 C9130-60004 8-5 7
Formatter PCB C4084-69001 C4084-69001 C4227-69001 8-5 6
Fuser, 110V RG5-5154-000CN
C4084-69002* RG5-5154-000CN
C4084-69002* RG5-5154-000CN
C4084-69002* 8-8 11
Fuser, 220V RG5-5155-000CN
C4084-69003* RG5-5155-000CN
C4084-69003* RG5-5155-000CN
C4084-69003* 8-8 11
Gear assembly RG5-3228-000CN RG5-3228-000CN RG5-3228-000CN 8-14 9
Gear, 125T RS6-0176-000CN RS6-0176-000CN RS6-0176-000CN 8-11 4
Gear, 16T RS6-0151-000CN RS6-0151-000CN RS6-0151-000CN 8-14 15
Gear, 17T RS6-0158-000CN RS6-0158-000CN RS6-0158-000CN 8-13 1
Gear, 17T RS6-0158-000CN RS6-0158-000CN RS6-0158-000CN 8-13 4
Gear, 18T RS6-0140-000CN RS6-0140-000CN RS6-0140-000CN 8-13 6
Gear, 18T RS6-0139-000CN RS6-0139-000CN RS6-0139-000CN 8-14 4
Gear, 18T RS6-0139-000CN RS6-0139-000CN RS6-0139-000CN 8-14 13
Gear, 18T/14T RS6-0157-000CN RS6-0157-000CN RS6-0157-000CN 8-13 2
Gear, 18T/52T RF5-2161-000CN RF5-2161-000CN RF5-2161-000CN 8-13 22
Gear, 19T RS6-0141-000CN RS6-0141-000CN RS6-0141-000CN 8-13 7
Gear, 20T RS6-0138-000CN RS6-0138-000CN RS6-0138-000CN 8-13 18
Gear, 24T/37T RS6-0163-000CN RS6-0163-000CN RS6-0163-000CN 8-13 16
Description Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for HP
Color LaserJet
4550 printer
Figure Reference
C7085-90921 Chapter 8 Parts and diagrams 357
Gear, 26T RS6-0149-000CN RS6-0149-000CN RS6-0149-000CN 8-13 25
Gear, 26T RS6-0159-000CN RS6-0159-000CN RS6-0159-000CN 8-14 28
Gear, 26T/18T RS6-0137-000CN RS6-0137-000CN RS6-0137-000CN 8-14 8
Gear, 27T RS6-0135-000CN RS6-0135-000CN RS6-0135-000CN 8-13 9
Gear, 27T RS6-0135-000CN RS6-0135-000CN RS6-0135-000CN 8-13 10
Gear, 29T RS6-0150-000CN RS6-0150-000CN RS6-0150-000CN 8-13 29
Gear, 29T RS6-0150-000CN RS6-0150-000CN RS6-0150-000CN 8-13 30
Gear, 29T RS6-0152-000CN RS6-0152-000CN RS6-0152-000CN 8-14 17
Gear, 29T/17T RS6-0145-000CN RS6-0145-000CN RS6-0145-000CN 8-13 21
Gear, 30T/16T RS6-0134-000CN RS6-0134-000CN RS6-0134-000CN 8-13 11
Gear, 31T RS6-0136-000CN RS6-0136-000CN RS6-0136-000CN 8-13 13
Gear, 34T/15T RS6-0144-000CN RS6-0144-000CN RS6-0144-000CN 8-13 20
Gear, 35T RS6-0132-000CN RS6-0132-000CN RS6-0132-000CN 8-13 17
Gear, 37T RS6-0143-000CN RS6-0143-000CN RS6-0143-000CN 8-13 26
Gear, 37T/14T RS6-0133-000CN RS6-0133-000CN RS6-0133-000CN 8-13 19
Gear, 39T/31T RS6-0154-000CN RS6-0154-000CN RS6-0154-000CN 8-14 11
Gear, 47T RS6-0147-000CN RS6-0147-000CN RS6-0147-000CN 8-13 15
Gear, 49T RS6-0153-000CN RS6-0153-000CN RS6-0153-000CN 8-14 12
Gear, 52T RS6-0146-000CN RS6-0146-000CN RS6-0146-000CN 8-13 23
Gear, 53T RS6-0155-000CN RS6-0155-000CN RS6-0155-000CN 8-14 10
Gear, 53T/46T RS6-0156-000CN RS6-0156-000CN RS6-0156-000CN 8-13 3
Guide, cable RB2-1277-000CN RB2-1277-000CN RB2-1277-000CN 8-9 3
Guide, cable, lower RB2-1456-000CN RB2-1456-000CN RB2-1456-000CN 8-10 13
Guide, upper drum drawer
cable RB2-1457-000CN N/A N/A 8-10 1
Handle, ITB drawer RB2-1361-000CN RB2-1361-000CN RB2-1361-000CN 8-8 8
High-voltage power supply RG5-3285-000CN RG5-5165-000CN RG5-5165-000CN 8-8 4
ICL cam assembly RG5-3242-000CN RG5-3242-000CN RG5-3242-000CN 8-14 19
Indicator, paper level RB1-9009-000CN RB1-9009-000CN RB1-9009-000CN 8-17 5
Interconnect PCB RG5-3808-000CN RG5-3808-000CN RG5-3808-000CN 8-5 3
Interconnect PCB RG5-3808-000CN RG5-3808-000CN RG5-3808-000CN 8-9 2
I/O card C4081-60001 C4081-60001 C4207-60001 8-5 8
ITB assembly RG5-5173-000CN RG5-5173-000CN RG5-5173-000CN 8-8 6
ITB cam assembly RG5-3241-000CN RG5-3241-000CN RG5-3241-000CN 8-14 21
ITB drawer assembly RG5-5120-100CN RG5-5120-100CN RG5-5120-100CN 8-8 7
ITB drawer connector VS1-6174-014CN VS1-6174-014CN VS1-6174-014CN 8-12 6
Kit, carousel flap C4084-67909 C4084-67907 C4084-67907 8-11 14
Kit, fuser deflector C4084-67906 C4084-67906 C4084-67906 8-8 12
Kit, imaging drum drawer RG5-5230-000CN N/A N/A Not shown
Laser/scanner assembly RG5-5175-000CN RG5-5175-000CN RG5-5175-000CN 8-10 9
Lever, sensor RB2-0576-000CN RB2-0576-000CN RB2-0576-000CN 8-14 2
Limiter, torque RB1-8974-000CN RB1-8974-000CN RB1-8974-000CN 8-17 3
Link rowel RB2-0614-000CN RB2-0614-000CN RB2-0614-000CN 8-14 25
Metal tab, Tray 2 RB2-0593-000CN RB2-0593-000CN RB2-0593-000CN 8/11 35
Microswitch WC2-5330-000CN WC2-5330-000CN WC2-5330-000CN 8-10 7
Microswitch, ITB WC2-5330-000CN WC2-5330-000CN WC2-5330-000CN 8-12 2
Motor (M1), fusing
assembly RG5-3227-000CN RG5-3227-000CN RG5-3227-000CN 8-13 24
Motor(M2), pick-up RH7-1343-000CN RH7-1343-000CN RH7-1343-000CN 8-13 14
Paper feed PCB RG5-3810-000CN RG5-3810-000CN RG5-3810-000CN 8-5 5
Paper feed PCB assembly RG5-3810-000CN RG5-3810-000CN RG5-3810-000CN 8-14 18
Paper size sensor PCB RG5-3816-000CN RG5-3816-000CN RG5-3816-000CN 8-5 4
Description Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for HP
Color LaserJet
4550 printer
Figure Reference
358 Parts and diagrams C7085-90921
Plate, left RF5-2094-000CN RF5-2094-000CN RF5-2094-000CN 8-14 29
Plate, right RF5-2095-000CN RF5-2095-000CN RF5-2095-000CN 8-14 31
Plate support RF5-2138-000CN N/A N/A 8-14 27
Power supply, 110V RH3-2219-000CN RH3-2219-000CN RH3-2219-000CN 8-8 3
Power supply, 220V RH3-2220-000CN RH3-2220-000CN RH3-2220-000CN 8-8 3
Rod, delivery RB2-1284-000CN RB2-1284-000CN RB2-1284-000CN 8-8 14
Roller RF5-2092-000CN RF5-2092-000CN RF5-2092-000CN 8-13 5
Roller RB2-0717-000CN RB2-0717-000CN RB2-0717-000CN 8-16 1
Roller RB2-0744-000CN RB2-0744-000CN RB2-0744-000CN 8-16 2
Roller, paper pick RB1-8865-000CN RB1-8865-000CN RB1-8865-000CN 8-14 5
Roller, separation RF5-1885-000CN RF5-1885-000CN RF5-1885-000CN 8-17 4
Roller, separation RF5-1885-000CN RF5-1885-000CN RF5-1885-000CN 8-18
Roller, transfer RF5-2112-000CN RF5-2112-000CN RF5-2112-000CN 8-9 5
Rowel swing assembly RG5-4696-000CN RG5-4696-000CN RG5-4696-000CN 8-14 23
Sensor (PS3), last paper WG8-5364-000CN WG8-5364-000CN WG8-5364-000CN 8-16 3
Sensor (PS4), multi-
purpose tray paper WG8-5309-000CN WG8-5309-000CN WG8-5309-000CN 8-16 4
Sensor (PS6), fusing unit
pressure release WG8-5309-000CN WG8-5309-000CN WG8-5309-000CN 8-12 4
Sensor (PS7), delivery
paper FH7-7313-000CN FH7-7313-000CN FH7-7313-000CN 8-12 3
Sensor (PS8), cassette
paper WG8-5309-000CN WG8-5309-000CN WG8-5309-000CN 8-13 32
Sensor (PS10), carousel
position WG8-5362-000CN WG8-5362-000CN WG8-5362-000CN 8-11 10
Sensor, continuous toner
level N/A N/A RG5-5247-000CN
Sensor (PS12), toner level RG5-3355-000CN RG5-3355-000CN RG5-3355-000CN 8-11 9
Sensor (PS13), waste
toner RG5-3292-000CN RG5-3292-000CN RG5-3292-000CN 8-10 2
Sensor (PS14), density RG5-3281-000CN RG5-5149-000CN RG5-5149-000CN 8-15 2
Sensor, paper size RG5-3234-000CN RG5-3234-000CN RG5-3234-000CN 8-13 27
Shaft, paper pick RB2-0545-000CN RB2-0545-000CN RB2-0545-000CN 8-14 6
Solenoid, Tray 2 feed
(SL2) RG5-3245-000CN RG5-5119-000CN RG5-5119-000CN 8-13 8
Spacer RS5-6210-000CN RS5-6210-000CN RS5-6210-000CN 8-11 2
Spring, grounding RB2-0981-000CN RB2-0981-000CN RB2-0981-000CN
Spring tension RS5-2800-000CN RS5-2800-000CN RS5-2800-000CN 8-14 24
Spring, tension RS5-2754-000CN RS5-2754-000CN RS5-2754-000CN 8-8 15
Spring, toner flap RS5-2739-000CN RS5-2739-000CN RS5-2739-000CN 8-11 12
Spring, torsion RB1-9016-000CN RB1-9016-000CN RB1-9016-000CN 8-17 8
Spring, Tray 2 pickup
tension RS5-2794-000CN RS5-2794-000CN RS5-2794-000CN 8-13 33
Strap, cover support RB2-1556-000CN RB2-1556-000CN RB2-1556-000CN 8-8 5
Transfer assembly,
secondary RG5-3235-000CN RG5-5115-000CN RG5-5115-000CN 8-14 26
Transfer cam assembly RG5-3240-000CN RG5-5118-000CN RG5-5118-000CN 8-14 7
Tray, extension RB2-1215-000CN RB2-1215-000CN RB2-1215-000CN 8-6 7
*These parts require exchange
Description Parts for 4500
series xxG... and
below
Parts for 4500
series xxH... and
above
Parts for HP
Color LaserJet
4550 printer
Figure Reference
C7085-90921 Chapter 8 Parts and diagrams 359
Numerical parts list
CAUTION Two versions of the HP Color LaserJet 4500 series printers are available. Before ordering parts, you
will need to identify which printer version you are servicing. For more information, see page 329. The
4550 series has some different service parts from the 4500 series.
Table 8-19 Numerical parts list
Part number Description Figure Reference
C4081-60001 I/O Card (4500 only) 8-3 8
C4082-67901 500-sheet paper feeder 8-16 1
C4083-67901 Duplex unit 8-17 1
C4084-60004 Firmware DIMM (4500 only) 8-3 6
C4084-67906 Kit, fuser deflector 8-6 12
C4084-67907 Kit, carousel flap 8-9 14
C4084-69004 Formatter PCB (4500) 8-3 6
C4084-69002* Fuser, 110V 8-6 11
C4084-69003* Fuser, 220V 8-6 11
C4207-60001 I/O card 8-3 8
C4227-69001* Formatter PCB (4550 only) 8-3 6
C9130-60001 Firmware DIMM 8-3 7
Cap, toner flap 8-9 13
Cable, fan 8-6 1
Bearing, carousel 8-9 3
FH7-7313-000CN Sensor (PS7), delivery paper 8-10 3
RB1-8865-000CN Roller, paper pick 8-12 5
RB1-8974-000CN Limiter, torque 8-15 3
RB1-9001-000CN Cover, roller 8-15 2
RB1-9009-000CN Indicator, paper level 8-15 5
RB1-9012-000CN Arm, lifter, left 8-15 6
RB1-9013-000CN Arm, lifter, right 8-15 7
RB1-9016-000CN Spring, torsion 8-15 8
RB2-0545-000CN Shaft, paper pick 8-12 6
RB2-0561-000CN Clutch, one-way 8-12 20
RB2-0561-000CN Clutch, one-way 8-12 22
RB2-0572-000CN Clutch, one-way 8-12 3
RB2-0576-000CN Lever, sensor 8-12 2
RB2-0593-000CN Metal tab, Tray 2 8-11 35
RB2-0614-000CN Link rowel 8-12 25
RB2-0717-000CN Roller 8-14 1
RB2-0744-000CN Roller 8-14 2
RB2-0916-000CN Cover, connector 8-13 3
360 Parts and diagrams C7085-90921
RB2-0964-000CN Cap, toner flap 8-9 13
RB2-0981-000CN Spring, grounding 8-9 17
RB2-1130-000CN Bushing, drum drawer 8-13 5
RB2-1158-000CN Bushing, ITB, left 8-8 6
RB2-1180-000CN Cover, cable 8-8 5
RB2-1203-000CN Cover, right side 8-4 1
RB2-1205-000CN Cover, rear 8-4 12
RB2-1206-000CN Cover, lower rear 8-4 10
RB2-1215-000CN Tray, extension 8-4 7
RB2-1224-000CN Cover, connector 8-4 2
RB2-1277-000CN Guide, cable 8-7 3
RB2-1282-000CN Filter, air (large) 8-6 17
RB2-1283-000CN Filter, air (small) 8-6 9
RB2-1284-000CN Rod, delivery 8-6 14
RB2-1361-000CN Handle, ITB drawer 8-6 8
RB2-1456-000CN Guide, cable, lower 8-8 13
RB2-1457-000CN Guide, upper drum drawer cable 8-8 1
RB2-1556-000CN Strap, cover support 8-6 5
RB2-5185-000CN Bushing, ITB, left 8-8 6
RF5-1885-000CN Roller, separation 8-15 4
RF5-1885-000CN Roller, separation 8-16
RF5-2076-000CN Cover, toner access 8-5 2
RF5-2092-000CN Roller 8-11 5
RF5-2112-000CN Roller, transfer 8-7 5
RF5-2138-000CN Plate support 8-12 27
RF5-2152-000CN Connector 8-13 4
RF5-2161-000CN Gear, 18T/52T 8-11 22
RF5-3137-000CN Cover, toner access 8-5 2
RG5-3170-000CN Drum drive assembly 8-7 7
RG5-3226-000CN Feeder assembly 8-10 5
RG5-3227-000CN Motor (M1), fusing assembly 8-11 24
RG5-3228-000CN Gear assembly 8-12 9
RG5-3234-000CN Sensor, paper size 8-11 27
RG5-3235-000CN Transfer assembly, secondary 8-12 26
RG5-3240-000CN Transfer cam assembly 8-12 7
RG5-3241-000CN ITB cam assembly 8-12 21
RG5-3242-000CN ICL cam assembly 8-12 19
RG5-3245-000CN Solenoid, Tray 2 feed (SL2) 8-11 8
RG5-3281-000CN Sensor (PS14), density 8-13 2
RG5-3285-000CN High-voltage power supply 8-6 4
Table 8-19 Numerical parts list
Part number Description Figure Reference
C7085-90921 Chapter 8 Parts and diagrams 361
RG5-3292-000CN Sensor (PS13), waste toner 8-8 2
RG5-3296-030CN Drawer switch assembly 8-8 8
RG5-3300-000CN Cover, top 8-5 1
RG5-3309-000CN Carousel brake assembly 8-8 12
RG5-3310-000CN Cover, right front 8-4 3
RG5-3313-000CN Cover, left side 8-4 9
RG5-3319-000CN Drum bushing assembly 8-6 13
RG5-3320-000CN Cover, ITB drawer 8-4 6
RG5-3325-040CN Door, rear access 8-4 11
RG5-3345-000CN Control panel assembly 8-4 5
RG5-3355-000CN Sensor (PS12), toner assembly 8-9 9
RG5-3400-210CN Cassette, 250-sheet 8-15 1
RG5-3781-000CN Cable, main 8-7 4
RG5-3782-000CN Cable, laser 8-8 10
RG5-3783-000CN Cable, developer 8-6 2
RG5-3785-000CN Cable, paper feed 8-11 28
RG5-3786-000CN Cable, ITB 8-10 7
RG5-3787-000CN Cable, fusing/option 8-12 1
RG5-3795-000CN Cable, rotary 8-9 8
RG5-3802-000CN Cable, control panel 8-4 4
RG5-3808-000CN Interconnect PCB 8-3 3
RG5-3808-000CN Interconnect PCB 8-7 2
RG5-3809-000CN DC controller PCB 8-8 3
RG5-3810-000CN Paper feed PCB 8-3 5
RG5-3810-000CN Paper feed PCB assembly 8-12 18
RG5-3811-000CN Developing PCB 8-3 1
RG5-3811-000CN Developing PCB 8-9 5
RG5-3816-000CN Paper size sensor PCB 8-3 4
RG5-3886-000CN Cable, fusing connector 8-9 7
RG5-3887-000CN Cable, fan 8-6 1
RG5-3900-000CN 500-sheet paper cassette 8-16 2
RG5-4055-000CN Duplexing feeder assembly 8-17 2
RG5-4650-000CN Cable, fan 8-8 4
RG5-4651-000CN Cable, ITB switch 8-10 1
RG5-4696-000CN Rowel swing assembly 8-12 23
RG5-5115-000CN Transfer assembly, secondary 8-12 26
RG5-5117-000CN Feeder assembly 8-10 5
RG5-5118-000CN Transfer cam assembly 8-12 7
RG5-5119-000CN Solenoid, Tray 2 feed (SL2) 8-11 8
RG5-5120-100CN ITB drawer assembly 8-6 7
Table 8-19 Numerical parts list
Part number Description Figure Reference
362 Parts and diagrams C7085-90921
RG5-5135-000CN Face-down delivery assembly 8-6 16
RG5-5142-000CN Drum drawer assembly 8-7 6
RG5-5142-000CN Drum drawer assembly 8-13 1
RG5-5149-000CN Sensor (PS14), density 8-13 2
RG5-5150-000CN Cover, top 8-5 1
RG5-5151-000CN Cover, left side 8-4 9
RG5-5152-000CN Cover, drum drawer 8-4 8
RG5-5154-000CN Fuser, 110V 8-6 11
RG5-5155-000CN Fuser, 220V 8-6 11
RG5-5163-000CN Carousel brake assembly 8-8 12
RG5-5165-000CN High-voltage power supply 8-6 4
RG5-5170-000CN Door switch assembly 8-8 14B
RG5-5173-000CN ITB assembly 8-6 6
RG5-5175-000CN Laser/scanner assembly 8-8 9
RG5-5180-000CN Developing PCB 8-3 1
RG5-5180-000CN Developing PCB 8-9 5
RG5-5186-000CN Cable, main 8-7 4
RG5-5187-000CN Cable, developer 8-6 2
RG5-5195-000CN Cable, control panel 8-4 4
RG5-5209-000CN Carousel drive assembly 8-9 6
RG5-5230-000CN Drum drawer assembly 8-7 6
RG5-5230-000CN Drum drawer assembly 8-13 1
RG5-5230-000CN Kit, imaging drum drawer Not shown
RG5-5232-000CN Cover, drum drawer 8-4 8
RG5-5247-000CN Continuous toner level sensor 8-9 15
RG5-5249-000CN Carousel assembly 8-9 11
RG5-5254-000CN DC controller PCB 8-3 2
RG5-5254-000CN DC controller PCB 8-8 3
RG5-5444-000CN Cable, level sensor 8-9 16
RH2-5334-000CN Cable, laser (flat) 8-8 11
RH2-5335-000CN Cable, video interface 8-7 1
RH3-2219-000CN Power supply, 110V 8-6 3
RH3-2220-000CN Power supply, 220V 8-6 3
RH7-1343-000CN Motor (M2), pick-up 8-11 14
RH7-1346-000CN Fan, large 8-9 1
RH7-1407-000CN Fan, small 8-6 10
RH7-1435-000CN Fan, large 8-9 1
RH7-5176-000CN Clutch (CL2), electromagnetic 8-11 31
RH7-5178-000CN Clutch (CL3), electromagnetic 8-12 16
RH7-5180-000CN Clutch (CL4), electromagnetic 8-12 14
Table 8-19 Numerical parts list
Part number Description Figure Reference
C7085-90921 Chapter 8 Parts and diagrams 363
RS5-1293-000CN Bushing 8-11 12
RS5-1341-000CN Cone 8-11 34
RS5-2739-000CN Spring, toner flap 8-9 12
RS5-2754-000CN Spring, tension 8-6 15
RS5-2794-000CN Spring, Tray 2 pickup tension 8-11 33
RS5-2799-000CN Spring, tension 8-12 32
RS5-2800-000CN Spring, tension 8-12 24
RS5-6210-000CN Spacer 8-9 2
RS6-0132-000CN Gear, 35T 8-11 17
RS6-0133-000CN Gear, 37T/14T 8-11 19
RS6-0134-000CN Gear, 30T/16T 8-11 11
RS6-0135-000CN Gear, 27T 8-11 9
RS6-0135-000CN Gear, 27T 8-11 10
RS6-0136-000CN Gear, 31T 8-11 13
RS6-0137-000CN Gear, 26T/18T 8-12 8
RS6-0138-000CN Gear, 20T 8-11 18
RS6-0139-000CN Gear, 18T 8-12 4
RS6-0139-000CN Gear, 18T 8-12 13
RS6-0140-000CN Gear, 18T 8-11 6
RS6-0141-000CN Gear, 19T 8-11 7
RS6-0143-000CN Gear, 37T 8-11 26
RS6-0144-000CN Gear, 34T/15T 8-11 20
RS6-0145-000CN Gear, 29T/17T 8-11 21
RS6-0146-000CN Gear, 52T 8-11 23
RS6-0147-000CN Gear, 47T 8-11 15
RS6-0149-000CN Gear, 26T 8-11 25
RS6-0150-000CN Gear, 29T 8-11 29
RS6-0150-000CN Gear, 29T 8-11 30
RS6-0151-000CN Gear, 16T 8-12 15
RS6-0152-000CN Gear, 29T 8-12 17
RS6-0153-000CN Gear, 49T 8-12 12
RS6-0154-000CN Gear, 39T/31T 8-12 11
RS6-0155-000CN Gear, 53T 8-12 10
RS6-0156-000CN Gear, 53T/46T 8-11 3
RS6-0157-000CN Gear, 18T/14T 8-11 2
RS6-0158-000CN Gear, 17T 8-11 1
RS6-0158-000CN Gear, 17T 8-11 4
RS6-0159-000CN Gear, 26T 8-12 28
RS6-0163-000CN Gear, 24T/37T 8-11 16
RS6-0176-000CN Gear, 125T 8-9 4
Table 8-19 Numerical parts list
Part number Description Figure Reference
364 Parts and diagrams C7085-90921
VS1-6173-014CN Connector not shown
VS1-6174-014CN ITB drawer connector 8-10 6
WC2-5330-000CN Microswitch 8-8 7
WC2-5330-000CN Microswitch, ITB 8-10 2
WG8-5309-000CN Sensor (PS8), cassette paper 8-11 32
WG8-5309-000CN Sensor (PS6), fusing unit pressure release 8-10 4
WG8-5309-000CN Sensor (PS4), multi-purpose tray paper 8-14 4
WG8-5362-000CN Sensor (PS10), carousel position 8-9 10
WG8-5364-000CN Sensor (PS3), last paper 8-14 3
XG9-0361-000CN Bearing, carousel 8-9 3
*These parts require exchange
Table 8-19 Numerical parts list
Part number Description Figure Reference
C7085-90921 Index 365
Index
Numerics
10/100Base-TX networks 66
10Base2 networks 65
10BaseT networks 66
A
AC bias 105
AC/DC power supply 135
access denied 73
accessories
cleaning 78
ordering 41, 325
acoustic emissions 23
Acrobat, Adobe 249
adding memory 98
adhesive labels
printing 32
supported sizes 29
adjusting colors
automatic 246
balance 250
Adobe Acrobat 249
Adobe Illustrator 249
Adobe InDesign 250
Adobe PageMaker 249
Adobe PhotoShop 247, 249
air filters
locating 84
replacing 91
alerts page 286
alphabetical lists
error messages 217
part numbers 355
altitude 22
ammonia-based cleaners, avoiding 78
applications
PANTONE support 249
sRGB support 247
ASCII escape sequence 75
assemblies
locating 25
remanufactured 42
removing 139
replacing 40
atmospheric pressure 23
automatic color adjustment 246
automatic PANTONE calibration 248
B
B connector 58
backgrounds, troubleshooting
gray 258
scatter 254
balance, adjusting
color 250
gray 252
banding, troubleshooting 254
base memory 16
base models 14
beam detect (BD) mirror 120
bidirectional parallel cable
connecting 59
pin configuration 60
specifications 58
troubleshooting 268
black lines, troubleshooting 255, 261
black pages, troubleshooting 255, 257
black toner cartridges
density setting 252
installing 51, 54
part numbers 327
replacement intervals 142
replacing 86
blade, cleaning 109
blank pages, troubleshooting 256
blurry images 257
BNC ports 65
board, formatter 98
brush, cleaning 85
C
C connector 26, 58
cabinet, ordering 326
cables
DIN-8 72
Ethernet 65
parallel 58
part numbers 325
ThinLan 65
calibration
PANTONE 248
toner cartridges 54
Calibration Menu 281
caliper, transparencies 31
cams
diagrams 348
ITB 114
pick-up 124
removing 208
secondary transfer roller 115
capacity
circuit 22
input trays 29
output bins 17
cardstock
printing 32
supported sizes 29
carousel, toner
assembly diagrams 331
components 118
drive assembly, removing 179
housing assembly
removing 200
motor (M3) 118, 133
operations 118
position sensor (PS10) 118, 119
cartridge, photosensitive drum 112
cassette feed solenoid (SL2) 123, 188
cassette paper sensor (PS8) 123
CD, service part information 42
Central Processing Unit (CPU) 68
366 Index C7085-90921
characters, troubleshooting
dropouts 257
voids 257
wavy 262
charge
development 106
eliminator 108
laser exposure 106
primary 105
transfer 107
checklist, pre-troubleshooting 212
circuit
assemblies 40
breaker, diagram 317
capacity 22
cleaning
printer and accessories 78
toner density sensor 85
waste toner operation 109, 113
cleaning brush 85
cleaning roller clutch (CL3)
operations 114
removing 189
cleaning roller, operations 114
clearing
error messages 217, 282
event log 297
clothing, toner on 37
clutches
CL1 (registration) 123
CL2 (ITB unit contact/separation) 114, 116, 190
CL3 (ITB cleaning roller) 114, 189
CL4 (secondary transfer roller) 114, 115, 192
diagrams 309, 311, 314
removing 189
CMYK 248
coated media 30
collimator lens 120
color
automatic adjustment 246
balance, adjusting 250
calibration 54
Calibration Menu 281
CMYK 248
density test 243
halftone settings 245
HP ColorSmart II 246
map settings 246
missing 260
page count tracking 296
PANTONE matching 248
PostScript 250
settings 244, 246
software applications 249
sRGB 246
troubleshooting 257
variation 244
Color LaserJet 4500 family printer models 14
Color LaserJet Transparencies, ordering 326
color print speed 17
colored paper 31
ColorLaserJet Soft Gloss Paper 326
colorless output, troubleshooting 257
ColorSmart II 246
commands
DOS 269
PJL 269
Commercial Service and Support Organization-America (CSSO-A) 41
Commercial Service and Support Organization-Europe (CSSO-E) 41
communication, bidirectional
establishing 58
troubleshooting 268
compact disc, service part information 42
components
diagrams 337
replacing 40, 139
condensation 213
Configuration Menu 276
configuration page 287
configure printer page 286
configuring
EIO 67
network parameters 70
Novell NetWare 70, 71
Windows networks 71
connecting
10/100Base-TX network 66
10Base2 network 65
10BaseT network 66
LocalTalk networks 64
networks 64
parallel cable 59
power cord 50
connectors, diagrams 314, 318, 319
consumables
HP 83
locating 84
ordering 41, 325
replacement intervals 83, 142
replacing 85
status information 290
storing 23
control panel
Calibration Menu 281
changing overlay 154
Configuration Menu 276
display language 61
EIO Menu 280
error messages 217
formatter PCB 135
I/O menu 280
Information Menu 273
locating 25
locking 73
menu map 271
Paper Handling Menu 274
Printing Menu 278
Private/Stored Jobs Menu 284
Quick Copy Jobs Menu 283
removing 153
Resets Menu 282
service mode 293
control panel overlays
installing 154
ordering 326
controller, DC
assembly diagrams 333
connectors 318
formatter PCB 135
operations 132
removing 158
replacing 297
Copy Jobs Menu, Quick 283
cord, power
connecting 50
unplugging 139
CorelDRAW 247, 249
C7085-90921 Index 367
count, page
color 296
consumables 142
definition 80
ITB 114
printing report 291
total 297
counter, ITB 114
country of origin, determining 18
covers, cleaning 78
covers, removing
diagrams 335
drum drawer 149
front right 155
ITB drawer 151
left side 145
middle drawer 151
protective scanner 139
right rear 148
right side 146
switch assembly, top 161
top 144
top drawer 149
CPU 68
cradle, formatter PCB 169
CSSO-A (Commercial Service and Support Organization-America) 41
CSSO-E (Commercial Service and Support Organization-Europe) 41
cutouts 30
cyan toner cartridges
adjusting density 251
installing 51, 54
part numbers 327
replacement intervals 142
replacing 86
cylindrical lens 120
D
Dainippon Press (DIC) 248
dark gray release button 51
Data Link Control (DLC) 72
DC bias 105
DC controller
assembly diagrams 333
connectors 318
formatter PCB 135
operations 132
removing 158
replacing 297
default settings
Configuration Menu 276
print jobs 278
restoring 282
defeat, rear door switch 316
defects, troubleshooting
images 253
repetitive 265
transparencies 263
delivery deflector solenoid (SL3102) 129
delivery paper sensor (PS7) 122, 127, 312
delivery rollers 127
Deneba Canvas 249
densitometer assembly, removing 166
density sensor, toner (PS14)
cleaning 85
operations 111
density, adjusting
color 250
print 243
depth, printer 23
Designer, Micrografx 249
DeskJet transparencies, avoiding 31
Detail option 245
detection port, toner cartridge 120
detection switches, paper size 123
developer
assembly diagrams 333
testing 303
developer sleeve 118, 119
developing carousel assembly 343
developing PCB, removing 159
development process 106
device page set 286
diagnostics
control panel 271
engine 302
formatter 300
mode, entering 300
using 40
diagrams, internal components 337
DIC (Dainippon Press) 248
dimensions, printer 23
DIMMs
adding 98
localized 325
ordering 326
supported 16
DIN-8 cable 72
DIN-8 port 64
diodes 111, 120
disconnecting power 139
display language, selecting 61
distorted images 257
DLC (Data Link Control) 72
documentation, ordering 43
doors
diagrams 335
rear, removing 147
sensor test 304
switches 135
DOS commands 269
DRAM DIMMs
adding 98
supported 16
drawer assembly, upper 350
drawers, removing
drum assembly 112, 163
middle 152
switch assembly 182
top assembly 163
drive assemblies, removing
carousel 179
drum 176
drivers, printer
color output 244
ordering 43
settings 69
dropouts, troubleshooting 257
drum drawer
assembly, removing 163
cover, removing 149
locating 25
versions 335
drum drive assembly, removing 176
drum kits
life span 83
ordering 325
replacement intervals 142
drum motor (M4) 134
368 Index C7085-90921
drum test 303
drums
imaging, installing 57
imaging, replacing 80, 88
life span 80
photosensitive 112
duplex feed motor (M3101) 129
duplex feed roller pressure release solenoid (SL3101) 129
duplex pick-up paper sensor (PS3104) 122, 129
duplex pick-up sensor (PS3103) 122, 130
duplex unit
assembly diagrams 354
connector diagrams 320
locating 25, 26
models with 15
ordering 326
supported media 30
duplexing
drum life 80
glossy paper, avoiding 30
paper path 128
pick-up operations 131
duty cycle, maximum 24
E
edges, detecting
leading 114
trailing 129
EDO DIMMs, not supported 16
EEPROMs 112
EIO
configuration 67
event log, printing 292
Menu 280
slots, locating 26
troubleshooting 268
electrical specifications 22
electrical surface resistivity 31
electrostatic discharge 139
eliminator, charge 108
e-mail page 286
embedded Web server 285
embossed media 30
emissions
acoustic 23
engine
diagnostics 302
testing 306
entering
diagnostics mode 300
service mode 293
envelopes
printing 32
supported sizes 29
environmental specifications 20, 22
environmental stewardship program 34
EPSF Charts 249
error logs, printing 292
error messages
alphabetical list 217
clearing 217, 282
jams 239
numerical list 226
ESD (electrostatic discharge) 139
ESD strap 140
Ethernet connections 65
Euro-standard CMYK 248
event log
clearing 297
printing 292
exchange program 42
exhaust fans 134
exiting diagnostic mode 300
exposure, laser 106, 120
Extended Data Output (EDO) DIMMs, not supported 16
F
face-down assembly, removing 199
face-down bin
delivering to 127
paper full sensor (PS9) 127, 224
face-up bin
delivering to 127
duplexing operations 129
faded print, troubleshooting 258, 259
fans
diagrams 310, 316
large fan housing, removing 178
large right side, removing 195
left side, removing 197
locations 133
motor 134
Fast InfraRed Receiver (FIR) 68
features, printer 15
feed PCB, removing 183
feed rollers
cleaning 78
operations 122
feeding operations
cassette 123, 126
duplex unit 128
manual 124
paper path 122
filters
locating 84
replacing 91
Finnish laser safety statement 38
FIR (Fast InfraRed Receiver) 68
firmware
replacing 307
upgrading 98
flags 118, 119
flat-blade screwdrivers 140
flowchart, troubleshooting 213
fonts
adding 98
localized DIMMs, ordering 325
standard 15
formatter
assembly diagrams 333
board, removing 98
diagnostics 300
operations 135
pan assembly, removing 170
processor 68
removing 169
replacing 297, 307
four color printing 248
Fractal Design Painter 249
Freehand, Macromedia 249
front door switch 135
front right cover, removing 155
full-page ghosting 258
C7085-90921 Index 369
fuser
assembly diagrams 330
cleaning 78
locating 84
maintenance count 296
replacing 92
fuser kits
life span 83
ordering 325
replacement intervals 142
replacing 92
status report, printing 290
fuses 317
fusing
operations 110
temperature specifications 31
fusing assembly, diagram 317
fusing delivery rollers 127
fusing motor (M1)
operations 114, 127, 133
removing 185
fusing unit pressure release sensor (PS6) 127, 312
G
gears
diagrams 346
removing 193
ghosting, full-page 258
glossy paper
duplexing, avoiding 30
HP Soft Gloss 326
printing 31
supported sizes 29
gray background, troubleshooting 258
gray balance 252
grayscale option 246
guides, ordering 43
H
halftone options 245
hard disk dependent menus 283
Hard disk file directory page 292
hard drives, included 14
heavy paper
printing 32
supported weights 29
height, printer 23
high-voltage power supply
operations 136
removing 174
home page set 286
home position detection sensor (PS5) 114, 223
home position sensor, side registration (PS3105) 130
horizontal lines, troubleshooting 254
housing, removing
carousel 200
large fan 178
HP Color LaserJet 4500 family printer models 14
HP Color LaserJet Soft Gloss Paper 326
HP Color LaserJet Transparencies 326
HP ColorSmart II 246
HP Distribution Center 43
HP JetAdmin software 67, 70
HP JetDirect print servers
connecting 10/100Base-TX 66
connecting 10Base2 65
connecting 10Base-T 66
installing 67
ports 64
supported configurations 71
HP LaserJet Family Print Media Guide 28
HP LaserJet Utility for Macintosh 70
HP LocalTalk Cable Kit 72
HP PCL 17
HP Support Assistant 42
HP Toner Cleaning Cloth 78
HP-UX 72
hubs, rollers 94
humidity
site requirements 20, 22
storing consumables 23
I
I/O Menu 280
I/O switching 58
IBM OS/2 LAN servers 72
ICC color profiles 249
identification page, device 286
Illustrator, Adobe 249
image formation system
operations 104
troubleshooting 243
images
aligning on page 114
defects, troubleshooting 253
definition 80
drum life 80
imaging drum
connector diagram 315
defects 265
installing 57
kits, status report 290
laser exposure 106, 120
life span 80
locating 84
primary charge 105
protecting 139
replacing 88
shipping 54
InDesign, Adobe 250
Information Menu 273
InfraRed Receiver, Fast (FIR) 68
initializing NVRAM 307
inkjet transparencies, avoiding 31
inks, specifications 33
input trays
capacity 29
locating 25
margins, setting 299
settings 274
supported media 29
installing
imaging drum 57
memory 98
software 59
toner cartridges, older versions 51
interfaces
EIO 67
parallel 58
settings 280
standard 17
troubleshooting 268
370 Index C7085-90921
internal assemblies
diagrams 337
removing 200
Internet Explorer, Microsoft 285
IP-based networks 285
IPX/SPX 71
IrDA-compliant 68
isolating problems 40
ITB
cleaning roller clutch (CL3) 114, 189
clutch assembly, removing 190
drawer cover, removing 151
home position detection sensor (PS5) 114, 223
lift cams 114
locating 25, 84
maintenance count 296
operations 113
paper path 122
replacing 90
secondary transfer roller 115
sensor diagrams 311
transfer operations 107
unit contact/separation clutch (CL2) 114, 116, 190
unit life sensor (PS1) 114
waste toner cleaning 109
J
jam sensors 122, 237
jams
checklist 241
error messages 239
locations 238
log, printing 292
recovery, enabling 242
sensors 122, 237
JetAdmin software 67, 70
JetDirect print servers
connecting 10/100Base-TX 66
connecting 10Base2 65
connecting 10Base-T 66
installing 67
ports 64
supported configurations 71
jobs, print
monochrome, affect on drum life 81
settings 278
short 80
K
kits
ordering 325
replacement intervals 142
replacing 89, 92
status report, printing 290
L
labels
printing 32
supported sizes 29
languages
changing control panel overlay 154
display 61
embedded Web server 286
localized DIMMs 325
printer job (PJL) 269
printer language support 17
universal exit (UEL) 269
laptop computers 68
large fan housing, removing 178
large right side fan, removing 195
laser
image exposure 106
operations 120
laser safety statements
Finland 38
United States 37
laser/scanner assembly, removing 157
LaserJet 4500 family printer models 14
LaserJet Family Print Media Guide 28
LaserJet Soft Gloss Paper 326
LaserJet Transparencies, ordering 326
LaserJet Utility for Macintosh 70
last paper detection roller 125
last paper sensor (PS3) 124, 125, 312
leading edge, detecting 114
LEDs 111
left side assemblies, removing 182
left side cover, removing 145
left side fan, removing 197
left side gears, removing 193
lenses 120
letterhead, printing 33
level detection, toner 119
level location 49
levels, security 74
life span
consumables 83
imaging drum 80
ITB 114, 296
kits 142
photosensitive drum cartridge 112
status page, printing 290
toner cartridges 83, 142
lift cams 114
lifting printer 49
light print, troubleshooting 259
light, affects on color variation 244
light-emitting diodes (LEDs) 111
lines, troubleshooting
black 255
horizontal 254
vertical 261
white 261
localized font DIMMs 325
LocalTalk networks
configuring 68
connecting 64
HP Cable Kit 72
location requirements 20, 21
locking control panel settings 73
log, event
clearing 297
printing 292
low toner cartridges, detecting 120
M
machine screws 141
Macintosh
DIN-8 connection 72
FIR compliance 68
HP LaserJet Utility 70
Macromedia Freehand 249
C7085-90921 Index 371
magenta toner cartridges
density settings 251
installing 51, 54
part numbers 327
replacement intervals 142
replacing 86
maintenance counts 296
male connectors 58
management, color 246
manual color adjustment 246
manual feeding
operations 124
solenoid (SL1) 124
maps
color 246
menu 271, 294
marbled output, troubleshooting 260
margins, setting 298
matching color
HP Color Smart II 246
PANTONE 248
variation 244
Material Data Safety Sheet (MSDS) 37
media
non-supported 30
ordering 326
selecting 28
sizes 29
special 31
specifications 241
storing 33
weights 29
memory
access location 26
adding 98
configuration report 288
duplex unit 15
localized font DIMMs 325
non-volatile (NVRAM) 100
NVRAM initialization 307
ordering 326
resetting 282
standard 16
supported 16
menu map, printing 271, 294
menus
Calibration 281
Configuration 276
EIO 280
hard disk dependent 283
I/O 280
Information 273
locking 73
Paper Handling 274
Printing 278
Private/Stored Jobs 284
Quick Copy Jobs 283
Resets 282
Service 296
messages, error
alphabetical list 217
clearing 217, 282
jams 239
numerical list 226
Micrografx Designer 249
Microsoft Internet Explorer 285
Microsoft Office 247, 249
Microsoft Publisher 249
middle drawer cover, removing 151
middle drawer, removing 152
mirrors 120
misfeeds 241
missing colors 260
model numbers 18
models
drum drawers 335
HP LaserJet 4500 14, 140
modes
diagnostics 300
service 293
monitors, affect on color 244, 247
monochrome print speed 17
motors
diagrams 310
fan 134
locations 133
M1 (fusing), operations 114, 127, 133
M1 (fusing), removing 185
M2 (pick-up), operations 122, 126, 133
M2 (pick-up), removing 187
M3 (carousel) 118, 133
M3101 (duplex feed) 129
M3102 (reversing) 129
M3103 (side registration) 129, 130
M4 (drum) 134
M5 (toner cartridge) 118, 134
removing 185, 187
mottled output, troubleshooting 260
moving printer 49
MS-DOS commands 269
MSDS (Material Data Safety Sheet) 37
multifeeds 241
multipart forms, avoiding 30
multipurpose tray sensor (PS4) 124, 312
N
Navigator, Netscape 285
NDS (Novell Directory Services) 71
needle-nose pliers 140
Netscape Navigator 285
networks
10/100Base-TX 66
10Base2 65
10BaseT 66
configuring parameters 70
connecting 64
EIO configuration 67
embedded Web server 285
IBM OS/2 LAN 72
LocalTalk 64
Novell NetWare 70
security 73, 74
troubleshooting 268
UNIX 72
Windows 71
noise, printer 23
non-volatile memory (NVRAM)
function 100
initializing 307
Novell Directory Services (NDS) 71
Novell NetWare, configuring 70, 71
numbers
model 18
part 355, 359
serial 18, 140, 296
numerical lists
error messages 226
part numbers 359
372 Index C7085-90921
NVRAM (non-volatile memory)
function 100
initializing 307
O
Office, Microsoft 247, 249
OHT sensor (PS301) 125
ordering
documentation 43
drivers 43
parts 41, 325
software 43
OS/2 servers, IBM 72
output bins
capacity 17
face-down 127
face-up 127
rear 26
top 25
overcurrent protection 136
overlays, control panel
installing 154
ordering 326
overvoltage protection 136
P
package contents 48
packing tape, removing 49
page count
color 296
consumables 142
definition 80
ITB 114
printing report 291
total 297
page sets, embedded Web server 285
PageMaker, Adobe 249
pages
black, troubleshooting 255
blank 256
last, detecting 125
leading edges, detecting 114
per month maximum 24
trailing edges, detecting 129
white 256
palettes, PANTONE 249
pan assembly, formatter 170
PANTONE colors 248
paper
non-supported 30
ordering 326
preprinted 33
recycled 33
selecting 28
Soft Gloss 326
specifications 241
supported sizes 29
paper feed PCB, removing 183
paper feed rollers
locating 84
replacing 94
paper feeder paper detection sensor (PS3001) 126
paper feeder paper-size detection switches (SW3001,3002,3003) 126
paper feeder pick-up solenoid (SL3001) 126
Paper Handling Menu 274
paper jams
checklist 241
error messages 239
locations 238
log, printing 292
recovery, enabling 242
sensors 122
paper path
duplex unit 128
jam checklist 241
operations 122
test 302
troubleshooting 237
paper pick rollers
cleaning 78
removing 205
paper pick-up assembly, diagrams 345
paper size
detection sensors 126
detection switches 123, 127, 313
Paper Handling Menu 274
paper size switch PCB, removing 181
paper sizes, supported 17, 29
paper transport assembly, removing 204
parallel cable
connecting 59
pin configuration 60
specifications 58
troubleshooting 268
parallel connector 26
parallel port 58
parameters, network 70
part numbers
alphabetical list 355
consumables 325
numerical list 359
parts
compact disc information 42
ordering 41
replacing 139
passwords, setting 74
PCBs, removing
assembly diagrams 333
developing 159
formatter 169
paper feed 183
paper size switch 181
PCL support 17
perforations 30
Phillips screwdrivers 140
phone numbers
Commercial Service ans Support Organizations 41
HP Distribution Center 43
ordering parts 41
ordering supplies 325
photoconductive material 105, 106
photodiodes 111
photosensitive drum
cartridge 112
operations 116
PhotoShop, Adobe 247, 249
pick-up assembly, diagrams 345
pick-up motor (M2)
operations 122, 126, 133
removing 187
pick-up rollers
operations 124
removing 205
pin configuration, parallel cable 60
C7085-90921 Index 373
pins, memory 98
PJL (Printer Job Language)
commands 269
Technical Reference Manual 75
placement requirements 20, 21
plates, waste toner transfer 109
pliers 140
Plug and Play 59
ports
BNC 65
FIR 68
LocalTalk 64
parallel 58
RJ-45 66
Posidrive screwdrivers 140
postcards
printing 32
supported sizes 29
PostScript
color matching 250
support 17
pouches, ESD 139
power
consumption 22
rating information 19
troubleshooting 216
power button 50
power cord
connecting 50
unplugging 139
power receptacle, locating 26
power supplies
AC/DC 135
duplex unit 128
high-voltage 136
removing 173
power switch (SW6)
locating 25
overcurrent protection 136
PowerSave
formatter PCB control 135
power consumption 22
settings 63
preprinted forms 33
presses, commercial 248
pressure release sensor, fusing unit (PS6) 127, 312
pressure release solenoid, duplex feed roller (S3101) 129
pressure, atmospheric 23
pre-troubleshooting checklist 212
primary charge roller 105
primary transfer 107
print in grayscale option 246
print jobs
monochrome, affect on drum life 81
settings 278
short 80
print media
guide 28
printer drivers
color output 244
ordering 43
settings 69
Printer Job Language (PJL)
commands 269
Technical Reference Manual 75
printer language support 17
printer status page 286
printing
configuration page 287
event log 292
menu map 271, 294
supplies status page 290
usage page 291
Printing Menu 278
prism mirror 120
Private/Stored Jobs Menu 284
processor 68
production number 18
Publisher, Microsoft 249
punched paper 30
Q
quality, troubleshooting 253
Quark Xpress 249
Quick Copy Jobs Menu 283
quick-reference guides, ordering 43
R
Radio Frequency Interference (RFI) shield, removing 156
raised spots, troubleshooting 259
raster images 249
rear assemblies, removing 195
rear door
interlock switch defeat 316
locating 26
removing 147
switch 135
rear output bin
capacity 17
locating 26
recovery, jam 242
recycled paper 33
registration adjustment 130
registration clutch (CL1) 123
registration page 297
registration paper sensor (PS2) 122, 123, 131
registration roller
cleaning 78
operations 123
regulatory information
power rating 19
release button
dark gray 51
top cover 25
remanufactured assemblies 42
removing
packing tape 49
parts, important notices 139
sealing tape 52
repair notices 139
repetitive defects
causes 265
ruler 266
transparencies 263
replacement intervals
consumables 83
imaging drum 80
ITB 114, 296
kits 142
photosensitive drum 112
status page, printing 290
toner cartridges 83, 142
374 Index C7085-90921
replacing
air filters 91
consumables 83, 85
fuser 92
fuser kit 92
gears 193
imaging drum 88
ITB 90
paper rollers 94
parts 139
toner cartridges 86
transfer kits 89
reservoir, waste toner 109
Resets Menu 282
resetting printer 97
retaining ring screws 141
reversed paper sensor (PS3101) 122, 129
reversing motor (M3102) 129
reversing operations, duplex unit 129
RFI (Radio Frequency Interference) shield, removing 156
RGB, Standard (sRGB) 246
right rear cover, removing 148
right rear fan, diagram 316
right side assemblies, removing 168
right side cover, removing 146
right side fan, removing 195
RISC processor 68
RJ-45 ports 66
rollers
cleaning methods 78
cleaning roller 114
feed 122
fusing delivery 127
last paper detection 125
pick-up 124
primary charge 105
primary transfer 107
registration 123
removing 205, 207
replacing 89, 94
secondary transfer 107, 115
transfer 114
ruler, repetitive defects 266
S
safety information 37
scanner
assembly, removing 157
operations 120
protective cover 139
scatter, background 254
Screen Match 246
screwdrivers 140
screws, types of 141
SDRAM DIMMs
adding 98
supported 16
sealing tape, removing 52
secondary transfer process 107
secondary transfer roller
operations 115
paper path 122
secondary transfer roller clutch (CL4)
operations 114, 115
removing 192
security page 286
security, network 73, 74
selecting media 28
self tapping screws 141
sensors
diagrams 308, 311, 314
paper jam 122, 237
PS1 (ITB unit life) 114
PS10 (carousel position) 118, 119
PS11 (toner cartridge contact/separation) 118, 119
PS12 (toner level) 118, 119
PS13 (waste toner) 113, 313
PS14 (toner density) 85, 111
PS2 (registration paper) 122, 123, 131
PS3 (last paper) 124, 125, 312
PS3001 (paper feeder paper detection) 126
PS301 (overhead transparency) 125
PS3101 (reversed paper) 122, 129
PS3103 (duplex pick-up) 122, 130
PS3104 (duplex pick-up paper) 122, 129
PS3105 (side registration home position) 130
PS4 (multipurpose tray) 124, 312
PS5 (home position detection) 114, 223
PS6 (fusing unit pressure release) 127, 312
PS7 (delivery paper) 122, 127, 312
PS8 (cassette paper) 123
PS9 (face-down bin paper full) 127, 224
testing 303, 304
separation pad
cleaning 78
operations 124
separation process 108
separation rollers
cleaning 78
locating 84
serial numbers
locating 18, 140
setting 296
server, embedded Web 285
service approach 40
service mode 293
settings
color 244, 246
color balance 250
Configuration Menu 276
halftone 245
interface 280
locking 73
margins 298
network security 74
paper trays 274
PowerSave 63
print jobs 278
printer drivers 69
registration values 297
restoring defaults 282
shafts, removing
cam 208
roller 205
sharkskin, troubleshooting 260
sharpness, settings 245
sheet-metal parts, handling 139
shipping printer 54
shutting down printer 139
side registration adjustment 130
side registration home position sensor (PS3105) 130
side registration motor (M3103) 129, 130
Simple Network Management Protocol (SNMP) 67
site requirements 20, 21
skewed images 257
slots
EIO 26
memory 16, 98
C7085-90921 Index 375
smart color 246
smeared toner 261
Smooth option 245
SNMP (Simple Network Management Protocol 67
Soft Gloss paper 326
software
installing 59
JetAdmin 67, 70
ordering 43
PANTONE applications 249
sRGB applications 247
Solaris 72
solenoids
diagrams 309, 314
removing 188
SL1 (manual feed) 124
SL2 (cassette feed) 123, 188
SL3001 (paper feeder pick-up) 126
SL3101 (duplex feed roller pressure release) 129
SL3102 (delivery deflector) 129
sound intensity level 24
space requirements 21
spacing chart, defects 266
special media, printing 31
specifications
electrical 22
environmental 22
media 29
preprinted paper 30
printer 23
site requirements 20
space requirements 21
speed, printing 17
spilled toner
cleaning 78
washing off clothing 37
spots, troubleshooting 259, 260
Standard RGB (sRGB) 246
Standard Web Offset Press (SWOP) 248
standby button 25, 50
standby mode
acoustic emissions 23
button for 50
power consumption 22
star wheel assembly, removing 206
static discharge 139
status pages
printer 286
supplies 290
stirrer, toner 120
stop position flags 118, 119
stored jobs menu 284
storing
consumables 23
media 33
printer 22
strap, ESD 140
streaks, troubleshooting
faded 258
transparencies 264
vertical 261
subassemblies 40
sunburn, troubleshooting 260
SunOS 72
supplies
ordering 325
status page, printing 290
Support Assistant, HP 42
surface resistivity, electrical 31
swatches, sRGB 249
sweeper strip 109
switch assembly, removing 161
switch boxes 268
switches
diagrams 313, 314
drawer assembly, removing 182
front door 135
paper size PCB, removing 181
rear door 135
rear door interlock defeat 316
SW3001,3002,3003 (paper feeder paper-size detection) 126
SW6 (power) 25, 136
SW801,802,803 (paper size detection) 123, 127, 313
SWOP (Standard Web Offset Press) 248
system requirements, Fast InfraRed Receiver (FIR) 68
T
T connectors 65
tape, removing
packing 49
sealing 52
TCP/IP 71
technical reference guides 43
temperature
ink requirements 30
maximum change rate 23
site requirements 20, 22
storing consumables 23
testing
developer 303
diagnostics mode, entering 300
door sensors 304
drum 303
engine 306
paper path 302
paper path sensors 303
printer operation 62
text, troubleshooting 257, 262
theory of operations
clutches 114
duplex unit 128
fusing 110
image formation system 104
ITB 113
laser/scanner 120
paper path 122
secondary transfer roller 115
toner carousel 118
waste toner cleaning 109, 113
ThinLan cables 65
TIFF files 249
toner
cleaning spilled 78
development process 106
fusing operations 110
smeared 261
stray, troubleshooting 259
washing off clothing 37
waste, cleaning 109, 113
toner cartridges
access cover 25
contact/separation sensor (PS11) 118, 119
installing older versions 51
level detection 120
life span 83
locating 84
motor (M5) 118, 134
part numbers 327
376 Index C7085-90921
replacement intervals 142
replacing 86
safety data sheet 37
shipping 54
status report, printing 290
transfer operations 107
Toner Cleaning Cloth, HP 78
toner density sensor (PS14)
cleaning 85
operations 111
toner level sensor (PS12) 118, 119
tools, required 140
top cover
release button 25
removing 144
switch assembly, removing 161
top drawer assembly, removing 163
top drawer cover, removing 149
top output bin
capacity 17
locating 25
top-of-page signal 114
total page count 297
tracking
color page count 296
fuser maintenance 296
page count 297
transfer maintenance 296
trailing edge, detecting 129
transfer kits
life span 83
ordering 325
replacement intervals 142
replacing 89
status report, printing 290
transfer maintenance count 296
transfer operations 107
transfer plates, waste toner 109
transfer roller
cleaning 78
locating 84
operations 114
removing 207
replacing 89
transparencies
defects, troubleshooting 263
detection sensor (PS301) 125
HP-supported 30
ordering 326
print speed 17
printing 31
supported sizes 29
transport assembly, removing 204
Tray 1
assembly diagrams 351
capacity 29
feeding operations 124
locating 25
margins, setting 299
sensor (PS4) 124, 312
settings 274
special media handling 32
supported media 29
Tray 2
assembly diagrams 352
capacity 29
cassette feed solenoid (SL2) 123, 188
feeding operations 123
locating 25
margins, setting 299
paper size switches 123
replacing paper rollers 94
sensors 123
settings 274
supported media 29
Tray 3
assembly diagrams 353
capacity 30
connector diagrams 320
feeding operations 126
locating 25
margins, setting 299
ordering 326
paper size switches 126
replacing paper rollers 96
settings 274
supported media 30
wiring diagram 321
trays, input
capacity 29
locating 25
margins, setting 299
settings 274
supported media 29
troubleshooting
checklist 212
color 243
communications 268
configuration page, printing 287
control panel 271
diagnostics mode 300
event log, printing 292
flowchart 213
image defects 253
image formation system 243
paper path 237
power 216
quality 253
supplies status page, printing 290
transparencies 263
usage page, printing 291
trus head screws 141
turning off printer 139
U
UEL (universal exit language) 269
unit life sensor, ITB (PS1) 114
universal exit language (UEL) 269
UNIX networks 72
unpacking 48, 49
unplugging power cord 139
upgrading firmware 98
upper drawer assembly 350
usage page, printing 291
user guides, ordering 43
V
vacuuming 78
values, registration 297
variation, color 244
vector graphics 249
ventilation 20
versions
drum drawers 335
printers 140
vertical banding, troubleshooting 255
vertical lines, troubleshooting 261
Vivid color map 246
C7085-90921 Index 377
voids, character 257
voltage
AC/DC power supply 135
duplex unit 128
exposed 213
high-voltage power supply 136
operating 19
overvoltage protection 136
paper feeder 126
part numbers 324
power consumption 22
primary charge 105
W
Warp servers 72
warranty statement 44
waste toner
cleaning operation 109, 113
sensor (PS13) 113, 313
wavy characters, troubleshooting 262
Web server, embedded 285
websites
HP 15
HP JetAdmin software 70
Material Data Safety Sheet (MSDS) 37
PANTONE palettes 249
product and support information 42
service part information 42
specifications 22
weight
media 29
printer 20, 23
wheel assembly, removing 206
white lines, troubleshooting 261
white pages, troubleshooting 256
width, printer 23
Windows
FIR compliance 68
network configurations 71
wiring diagrams 321
Word, Microsoft 249
X
Xpress, Quark 249
Y
yellow toner cartridges
density settings 251
installing 51, 54
part numbers 327
replacement intervals 142
replacing 86
*C7085-90921*
*C7085-90921*
C7085-90921
copyright © 2000
Hewlett-Packard Company
www.hp.com/support/lj4550
english
www.s-manuals.com

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