Hp Laserjet 4000 Series 4050 Users Manual Service

4000 Series, 4050 Series to the manual f9119dbc-6feb-4c84-9515-c92a2bfa2019

2015-02-09

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Contents
Chapter 1 Printer Description
Chapter 2 Service Approach
Chapter 3 Printer Operation
Chapter 4 Printer Maintenance
Chapter 5 Functional Information
Chapter 6 Removing and Replacing Parts
Chapter 7 Troubleshooting
Chapter 8 Parts and Diagrams
Index

HP LaserJet 4000 and 4050 Series Printers Service Manual

HP LaserJet 4000 and

4050 Series Printers

Service Manual

Printed on at least

50% Total Recycled Fiber with

at least 10% Post-Consumer Paper

Hewlett-Packard Co.

Printed in USA

Manual Part No.

C4251-91003

*C4251-91003*

C4251-91003

HP LaserJet 4000 and 4050

Series Printers

Service Manual _____________

Hewlett-Packard Company

11311 Chinden Boulevard

Boise, Idaho 83714 USA

Company 1999

Reproduction, adaptation, or

translation without prior written

permission is prohibited, except

as allowed under the copyright

laws.

Publication number

C4251-91003

First edition, April 1999

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

PostScript™ is a trademark of

Adobe Systems Incorporated

which may be registered in

certain jurisdictions.

CompuServe™ is a U.S.

trademark of CompuServe, Inc.

Windows® is a U.S. registered

trademarks of Microsoft

Corporation.

TrueType™ is a U.S. trademark

of Apple Computer, Inc.

ENERGY STAR® is a U.S.

registered service mark of the

U.S. EPA.

Contents-1

Contents

1 Printer Description

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

Printer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Model and Serial Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8

Site Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9

Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10

Environmental Requirements . . . . . . . . . . . . . . . . . . . . . . . . 1-11

Paper Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12

Supported Types of Paper. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15

Guidelines for Using Paper . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16

Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Transparencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19

Envelopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20

Card Stock and Heavy Paper . . . . . . . . . . . . . . . . . . . . . . . . 1-23

Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24

Laser Safety Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24

Canadian DOC Regulations . . . . . . . . . . . . . . . . . . . . . . . . . 1-24

FCC Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-25

Laser Statement for Finland . . . . . . . . . . . . . . . . . . . . . . . . . 1-26

Toner Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-27

Environmental Product Stewardship . . . . . . . . . . . . . . . . . . . 1-28

2 Service Approach

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Service Approach. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

Parts and Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Helpful Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4

Phone Numbers for Ordering. . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Exchange Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

Consumables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

World Wide Web . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6

HP Service Parts Information Compact Disc . . . . . . . . . . . . . . 2-6

HP Support Assistant Compact Disc . . . . . . . . . . . . . . . . . . . . 2-7

HP FIRST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7

Toner Cartridge Information. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9

Warranty Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

Contents-2

3 Printer Operation

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

Using the Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Control Panel Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Control Panel Lights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

Control Panel Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Settings and Defaults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

Control Panel Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5

Quick Copy Jobs Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Private/Stored Jobs Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

Information Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8

Paper Handling Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9

Print Quality Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12

Printing Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15

Configuration Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20

I/O Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-26

EIO Menu (Networked Printers). . . . . . . . . . . . . . . . . . . . . . . 3-29

Resets Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-31

Service Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-32

Service Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

Setting the Page Count, Maintenance Count, and

Serial Number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33

Cold Reset Paper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

Clear Event Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36

Testing the Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37

Resetting the Printer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38

System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39

MS-DOS System Configuration . . . . . . . . . . . . . . . . . . . . . . . 3-39

Parallel DOS Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39

Serial MS-DOS Commands. . . . . . . . . . . . . . . . . . . . . . . . . . 3-40

Printer I/O Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

Parallel Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

Serial Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41

4 Printer Maintenance

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

Cleaning the Printer and Accessories . . . . . . . . . . . . . . . . . . . . . . 4-2

Cleaning Spilled Toner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Preventative Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Reset Maintenance Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

Expected Life of Components . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

Contents-3

5 Functional Information

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

Power Supply System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

AC/DC Power Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2

Overcurrent Overvoltage Protection . . . . . . . . . . . . . . . . . . . . 5-3

High-voltage Power Distribution . . . . . . . . . . . . . . . . . . . . . . . 5-4

Toner Cartridge Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

Engine Controller System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

Engine Controller Board Inputs and Outputs. . . . . . . . . . . . . . 5-8

Laser and Scanner Drive. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

Paper Motion Monitoring and Control . . . . . . . . . . . . . . . . . . 5-12

Solenoids, Sensors, Clutches, and Switches . . . . . . . . . . . . 5-12

Engine Test Print . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13

Formatter System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

PowerSave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

Resolution Enhancement technology (REt). . . . . . . . . . . . . . 5-16

EconoMode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16

Input/Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17

CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

Printer Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18

Random Access Memory (RAM) . . . . . . . . . . . . . . . . . . . . . . 5-19

DIMM Slots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19

Page Protect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

PJL Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20

PML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

Control Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21

Image Formation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22

Toner Cartridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24

Photosensitive Drum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25

Writing the Image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28

Developing the Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29

Transferring the Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30

Image Fusing/Variable Fusing Temperature . . . . . . . . . . . . . 5-31

Paper Feed System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33

Clutches and Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-35

Printing from Tray 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-36

Printing from Tray 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-38

Printing from the Optional 500-sheet

Universal Tray . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-41

Envelope Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44

Duplexer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-46

Paper Jam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-48

Basic Sequence of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-49

Contents-4

6 Removing and Replacing Parts

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

Removal and Replacement Strategy . . . . . . . . . . . . . . . . . . . . . . . 6-2

Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

Removing Covers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Rear Right Side Cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

Top Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7

Left Side Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

Front Right Side Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Rear Cover/Rear Output Bin . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Tray 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15

Removing Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18

Fuser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18

Formatter Cage Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20

Output Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-21

Laser Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23

Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24

Main Motor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-25

Transfer Roller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26

Tray 1 Pickup Roller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-27

Tray 1 Pickup Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-29

Right Side Toner Cartridge Guide . . . . . . . . . . . . . . . . . . . . . 6-33

Registration Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-34

Paper Feed Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36

Formatter Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39

Gear Train . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40

Delivery Drive Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-41

Separating the Engine Module from the Paper Feed Module . . . 6-42

Engine Controller Board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-44

Paper Feed Rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48

Separation Rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49

Paper Feed Module Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50

Paper Feed Module Gear Train Assembly. . . . . . . . . . . . . . . 6-51

Paper Feed Module Side Rails . . . . . . . . . . . . . . . . . . . . . . . 6-52

Lower Paper Feed Module Plate (HP LaserJet 4000 T/4000 TN

and 4050 T/4050 TN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53

PCA Cover (HP LaserJet 4000 T/4000 TN and

4050 T/4050 TN). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54

PCA Cover (HP LaserJet 4000/4000 N and 4050/4050 N) . . 6-55

PCA Controller. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-56

Contents-5

7 Troubleshooting

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

Troubleshooting Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Troubleshooting Flowchart . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

Troubleshooting Flowchart (Continued). . . . . . . . . . . . . . . . . . 7-5

Troubleshooting the Printing System . . . . . . . . . . . . . . . . . . . . . . . 7-6

Preliminary Operating Checks . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

Power On. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Engine Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

Event Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13

Printer Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17

General Paper Path Troubleshooting . . . . . . . . . . . . . . . . . . 7-45

Information Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48

Image Quality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-54

Image System Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . 7-74

Interface Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-77

AUTOEXEC.BAT Standard Configurations . . . . . . . . . . . . . . 7-81

Reference Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-84

Locations of Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-84

Paper Path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-90

Engine Controller Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-93

Paper Size Detection Switches . . . . . . . . . . . . . . . . . . . . . . . 7-94

Motors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-96

Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-97

PCAs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-100

Sensors and Thermistor . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-102

Solenoids and Clutch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-105

Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-108

Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-110

8 Parts and Diagrams

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

How To Use the Parts Lists and Diagrams . . . . . . . . . . . . . . . . . . 8-2

Accessories and Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-4

Common Screws and Replacement Cables . . . . . . . . . . . . . . 8-6

Illustrations and Parts Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

Alphabetical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-58

Numerical Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-67

Contents-6

Overview 1-1

1Printer Description

Overview

This chapter discusses the following:

●Printer Features

●Identification

●Site Requirements

●Paper Specifications

●Safety Information

1-2 Printer Description

Printer Features

Table 1-1. Printer Features for the HP LaserJet 4000 Series Printer

Speed 17 pages per minute (ppm)

100 MHz RISC microprocessor

First page out = 15 sec.

Resolution 300 dpi with PCL5e/HP’s PostScriptTM Level 2 emulation (PS)

600 dpi with PCL5e/PS

HP FastRes 1200 (PCL6 only)

HP ProRes 1200 at half engine speed (PCL6, PS)

Typefaces 110 Scalable TrueTypeTM (80 built-in, 30 via HP FontSmart, all PS

and PCL accessible)

Memory Options HP LaserJet 4000/4000 T: 4 MB RAM standard

HP LaserJet 4000 N/4000 TN: 8 MB RAM standard

Optional Memory:

4, 8, 16, and 32 MB EDO DIMMs

4, 8, 16, 32, and 64 MB SDRAM DIMM

Mass Storage Options 2 and 4 MB Flash DIMMs

Greater than 1 GB hard disk

Interface Bidirectional IEEE 1284 compliant parallel interface

RS-232 9-pin serial

Paper Handling Connector (PHC)

10Base-T and 10Base-2 (HP LaserJet 4000 N/4000 TN)

LocalTalk

Optional Networking 10Base-T and 10Base-2

10/100Base-TX

Token Ring

LocalTalk

Expansion Slots 3 100-pin DIMM slots

2 Enhanced I/O (EIO) slots

Printer Features 1-3

Paper Trays 100-sheet Tray 1

●Size: 3 by 5 in to legal (76 by 127 mm to 216 by 356 mm)

500-sheet Tray 2 (HP LaserJet 4000/ 4000 N)

●Size: letter, legal, A4

250-sheet Trays 2 and 3 (HP LaserJet 4000 T/ 4000 TN)

●Size: letter, A4, executive, legal, B5 (ISO), B5 (JIS), A5

Optional Universal 500-sheet Tray

●Supports standard and custom sizes from 5.8 by 8.2 in (149

by 210 mm) to 8.5 by 14 in (216 by 356 mm).

Paper Path Straight through from Tray 1 to Rear Output Bin

or to Top Output Bin

Output Capacity 250-sheet Top Output Bin

50-sheet Rear Output Bin

Paper Handling Options Duplexer, Envelope Feeder, Optional 500-sheet Universal Tray

Assembly

Table 1-1. Printer Features for the HP LaserJet 4000 Series Printer (continued)

1-4 Printer Description

Table 1-2. Printer Features for the HP LaserJet 4050 Series Printer

Speed 17 pages per minute (ppm)

133 MHz RISC microprocessor

First page out = 15 sec.

“RIP ONCE” capability with 16 MB or hard disk option

Resolution 300 dpi with PCL5e/HP’s PostScriptTM Level 2 emulation (PS)

600 dpi with PCL5e/PS

HP FastRes 1200 (PCL6, PS)

HP ProRes 1200 at engine speed (17 ppm) (PCL6, PS)

Typefaces 110 Scalable TrueTypeTM

(80 built-in, 30 via HP FontSmart, all PS and PCL accessible)

Euro symbol

Memory Options HP LaserJet 4050/4050 T: 8 MB RAM standard

HP LaserJet 4050 N/4050 TN: 16MB RAM standard

Optional Memory:

4, 8, 16, MB EDO DIMMs

4, 8, 16, 32, 64 MB SDRAM DIMM

Mass Storage Options 2 and 4 MB Flash DIMMs

Greater than 1 GB hard disk

Expansion Slots 3 100-pin DIMM slots

2 enhanced I/O (EIO) slots

Interface Bidirectional IEEE 1284-compliant parallel

10/100Base-TX (HP LaserJet 4050 N/4050 TN)

HP Fast InfraRed Receiver (FIR)

RS232 9-pin serial

Paper Handling Connector (PHC)

Optional Networking 10Base-T and 10Base-2

10/100Base-TX

Token Ring

LocalTalk

Printer Features 1-5

Paper Trays 100-sheet Tray 1

●Size: 3 by 5 to legal (76 by 127 mm to 216 by 356 mm)

500-sheet Tray 2 (HP LaserJet 4050/ 4050 N)

●Size: letter, legal, A4

250-sheet Trays 2 and 3 (HP LaserJet 4050 T/ 4050 TN)

●Size: letter, A4, executive, legal, B5 (ISO), B5 (JIS), A5

Optional 500-sheet Universal Tray

●Supports standard and custom sizes from 5.8 by 8.2 in (149

by 210 mm) to 8.5 by 14 in (216 by 356 mm).

Paper Path Straight through from Tray 1 to Rear Output Bin

or to Top Output Bin

Output Capacity 250-sheet Top Output Bin

50-sheet Rear Output Bin

Paper Handling Options Duplexer, Envelope Feeder, Optional 500-sheet Universal Tray

Assembly

Table 1-2. Printer Features for the HP LaserJet 4050 Series Printer (continued)

1-6 Printer Description

Table 1-3. Comparison of HP LaserJet 4000 Series Printers

HP LaserJet

4000 HP LaserJet

4000 T HP LaserJet

4000 N HP LaserJet

4000 TN

Ethernet 10-T/ 10-2

LocalTalk optional optional standard standard

Max. # Input Bins 3434

Standard RAM 4 MB internal 4 MB internal 8 MB internal 8 MB internal

250-Sheet Tray not available 2 standard not available 2 standard

500-Sheet Tray standard not available standard not available

500-Sheet

Universal Tray optional optional optional optional

> 1 GB EIO Drive optional optional optional optional

Envelope Feeder optional optional optional optional

Duplexer optional optional optional optional

Printer Features 1-7

Table 1-4. Comparison of HP LaserJet 4050 Series Printers

HP LaserJet

4050 HP LaserJet

4050 T HP LaserJet

4050 N HP LaserJet

4050 TN

Ethernet 10-T/ 10-2

LocalTalk optional optional optional optional

10/100 Base TX optional optional standard standard

Max. # Input Bins 3434

Standard RAM 8 MB internal 8 MB internal 16 MB internal 16 MB internal

250-Sheet Tray not available 2 standard not available 2 standard

500-Sheet Tray standard not available standard not available

500-Sheet

Universal Tray optional optional optional optional

> 1 GB EIO Drive optional optional optional optional

Envelope Feeder optional optional optional optional

Duplexer optional optional optional optional

HP Fast InfraRed

Receiver (FIR) optional optional standard standard

1-8 Printer Description

Identification

Model and Serial Numbers

The model number and printer serial number are listed on an

identification label located under the top cover on the right side of the

printer.

The model number is alphanumeric, such as C4253A for the

HP LaserJet 4050 N printer.

The serial number contains information about the Country of Origin,

the Revision Level, the Production Code, and Production Number of

the printer. An example of a serial number is USBB123456.

The top label also contains power rating and regulatory information as

shown in Figure 1-1.

Figure 1-1 Sample Label

Site Requirements 1-9

Site Requirements

The following environmental specifications must be maintained to

ensure the proper operation of the printer. Consider the following

points before installing the printer:

●Install in a well-ventilated, dust-free area.

●Install on a hard, flat and continuous surface, with all four printer

feet level. Do not install on carpet or other soft surfaces.

●Ensure adequate power is supplied. Printer power requirements

are listed in Table 1-5. (Uninterruptable power supplies (UPSs)

are not recommended.)

●Install where temperature and humidity is stable, away from water

sources, humidifiers, air conditioners, refrigerators, or other major

appliances.

●Install away from direct sunlight, open flames, or ammonia fumes.

If the printer is placed near a window, make sure the window has

a curtain or blind to block any direct sunlight.

●Install with enough space around the printer for proper access

and ventilation.

●Install away from the direct flow of exhaust from air ventilation

systems.

Table 1-5. Electrical Specifications for the HP LaserJet 4000 and 4050 Series

Printers

Volts Frequency Amperes Watts (typical)

100-127 VAC±10% 50/60 Hz ± 3 Hz 8 A printing = 330 W

standby = 22 W

PowerSave On = 20 W

(EPA ENERGY STAR®)

220-240 VAC±10% 50/60 Hz ± 3 Hz 4 A printing = 330 W

standby = 22 W

PowerSave On = 20 W

(EPA ENERGY STAR®)

1-10 Printer Description

Space Requirements

Figure 1-2 Printer Dimensions

Printer Weight (without Toner Cartridge)

●HP LaserJet 4000/4000 N and 4050/4050 N printers:

39.27 lb (17.85 kg)

●HP LaserJet 4000 T/4000 TN and 4050 T/4050 TN printers:

45.66 lb (20.71 kg)

15.4 in

(39.0 cm)

16.77 in (42.6 cm)

printer only, Rear Output Bin closed

HP LaserJet

4000/4000 N and

4050/4050 N

18.5 in

(46.99 cm)

with cover open

13.3 in

(34.3 cm)

with cover closed

HP LaserJet

4000 T/4000 TN and

4050 T/4050 TN

20.1 in

(51.19 cm)

with cover open

15.5 in

(38.5 cm)

with cover closed

39.67 in (100.76 cm)

full length, trays and Rear Output Bin open

Site Requirements 1-11

Environmental Requirements

Table 1-6. Printer and Toner Cartridge Environmental Conditions

Item Operating Storage

Temperature 50-91° F (10-32° C) 32 to 95° F (0 to 35°C)

Relative Humidity 20-80% RH (with no

condensation) 10% to 95% RH

Table 1-7. Acoustic Emissions (Per ISO 9296)

Printer State Sound Power

Printing, 17 pages per minute

(ppm) Lwad= 6.6 bels (A)

Printing, 8 ppm Lwad= 6.2 bels (A)

PowerSave Lwad= 0 bels (A)

1-12 Printer Description

Paper Specifications

The following tables show paper specifications for the

HP LaserJet 4000 and 4050 series printer.

* The printer supports a wide range of paper sizes. Check the printer software for supported sizes.

To print custom-size paper see the user’s guide.

** Capacity may vary depending on paper weight and thickness, and environmental conditions.

*** Custom media must be fed short edge first (portrait).

* The printer supports a wide range of paper sizes. Check the printer software for supported sizes.

** Capacity may vary depending on paper weight and thickness, and environmental conditions.

Table 1-8. Paper Specifications, Tray 1

Supported

Paper Dimensions* Weight Capacity**

Minimum Size

(custom) 3 by 5 in***

(76 by 127 mm) 16 to 53 lb

(60 to 199 g/m2)100 sheets of 20 lb

(75 g/m2) paper

Maximum Size 8.5 by 14 in

(216 by 356 mm)

Transparencies

Same as minimum

and maximum paper

sizes listed above.

Thickness:

0.0039 in to 0.0045 in

(0.099 to 0.114 mm) 75 transparencies

Labels Thickness:

0.005 in to 0.007 in

(0.127 mm to

0.178 mm)

50 labels

Envelopes 20 to 28 lb

(75 to 105 g/m2)10 envelopes

Table 1-9. Paper Specifications, Tray 2

(HP LaserJet 4000/4000 N and 4050/4050 N)

Supported

Paper Dimensions* Weight Capacity**

Letter 8.5 by 11 in

(216 by 279 mm)

16 to 28 lb

(60 to 105 g/m2)

500 sheets of 20 lb

(75 g/m2) paper

50-100 transparencies

A4 8.3 by 11.7 in

(210 by 297 mm)

Legal 8.5 by 14 in

(216 by 356 mm)

Paper Specifications 1-13

* The printer supports a wide range of paper sizes. Check the printer software for supported sizes.

** Capacity may vary depending on paper weight and thickness, and environmental conditions.

*** To print custom-size paper see the user’s guide.

Table 1-10. Paper Specifications, Trays 2 and 3

(HP LaserJet 4000 T/4000 TN and 4050 T/4050 TN)

Supported

Paper Dimensions* Weight Capacity**

Letter 8.5 by 11 in

(216 by 279 mm)

16 to 28 lb

(60 to 105 g/m2)

250 sheets of 20 lb

(75 g/m2) paper

50-100 transparencies

A4 8.3 by 11.7 in

(210 by 297 mm)

Executive 7.3 by 10.5 in

(191 by 267 mm)

Legal 8.5 by 14 in

(216 by 356 mm)

B5 (ISO)

(custom***) 6.9 by 9.9 in

(176 by 250 mm)

B5 (JIS) 7.2 by 10 in

(182 by 257 mm)

A5 (custom***) 5.8 by 8.2 in

(148 by 210 mm)

1-14 Printer Description

* The printer supports a wide range of paper sizes. Check the printer software for supported sizes.

** Capacity may vary depending on paper weight and thickness, and environmental conditions.

*** To print custom-size paper see the user’s guide.

Table 1-11. Paper Specifications, Optional 500-Sheet Universal Tray

Supported

Paper Dimensions* Weight Capacity**

Letter 8.5 by 11 in

(216 by 279 mm)

16 to 28 lb

(60 to 105 g/m2)

500 sheets of 20 lb

(75 g/m2) paper

50-100 transparencies

A4 8.3 by 11.7 in

(210 by 297 mm)

Executive 7.3 by 10.5 in

(191 by 267 mm)

Executive JIS

(custom ***) 8.5 by 13 in

(216 by 330 mm)

16K (custom ***) 7.75 by 10.75 in

(197 by 273 mm)

Legal 8.5 by 14 in

(216 by 356 mm)

B5 (ISO)

(custom***) 6.9 by 9.9 in

(176 by 250 mm)

B5 (JIS) 7.2 by 10 in

(182 by 257 mm)

A5 (custom***) 5.8 by 8.2 in

(148 by 210 mm)

Custom*** 5.8 by 8.2 in

to 8.5 by 14 in

(149 by 210 mm

to 216 by 356 mm)

Paper Specifications 1-15

* The printer supports a wide range of paper sizes. Check the printer software for supported sizes.

** Capacity may vary depending on paper weight and thickness, and environmental conditions.

Supported Types of Paper

The printer supports the following types of paper:

Table 1-12. Paper Specifications, Optional Envelope Feeder

Supported

Paper Dimensions* Weight Capacity**

Minimum Size 3.5 by 6.3 in

(90 by 160 mm) 20 to 28 lb

(75 to 105 g/m2)75 envelopes

Maximum Size 7 by 10 in

(178 by 254 mm)

Table 1-13. Paper Specifications, Optional Duplex Printing Accessory

(Duplexer)

Dimensions Weight Capacity

Letter 8.5 by 11 in

(216 by 279 mm)

16 to 28 lb

(60 to 105 g/m2)not applicable

A4 8.3 by 11.7 in

(210 by 297 mm)

Executive 7.3 by 10.5 in

(191 by 267 mm)

Legal 8.5 by 14 in

(216 by 356 mm)

B5 (JIS) 7.2 by 10 in

(182 by 257 mm)

●plain ●preprinted

●letterhead ●transparency

●prepunched ●labels

●bond ●recycled

●color ●card stock

●rough ●user-defined (5 types)

1-16 Printer Description

Guidelines for Using Paper

For best results, use conventional 20 lb (75 g/m2) paper. Make sure

the paper is of good quality and free of cuts, nicks, tears, spots, loose

particles, dust, wrinkles, voids, and curled or bent edges.

If you are unsure what type of paper you are loading (such as bond or

recycled), check the label on the package of paper.

Some paper causes print quality problems, jamming, or damage to

the printer.

Table 1-14. Guidelines for Using Paper

Symptom Problem with Paper Solution

Poor print quality or Toner

adhesion.

Problems with feeding.

Too moist, too rough, too

smooth, or embossed; faulty

paper lot.

Try another kind of paper,

between 100-250 Sheffield,

4-6% moisture content.

Dropouts, jamming, curl. Stored improperly. Store paper flat in its

moisture-proof wrapping.

Increased gray background

shading. Too heavy. Use lighter paper.

Open the Rear Output Bin.

Excessive curl.

Problems with feeding. Too moist, wrong grain

direction or short-grain

construction.

Open the Rear Output Bin.

Use long-grain paper.

Jamming, damage to printer. Cutouts or perforations. Do not use paper with cutouts

or perforations.

Problems with feeding. Ragged edges. Use quality paper.

Paper Specifications 1-17

Note Do not use letterhead paper that is printed with low-temperature inks,

such as those used in some types of thermography.

Do not use raised letterhead.

The printer uses heat and pressure to fuse Toner to the paper. Make

sure that any colored paper or preprinted forms use inks that are

compatible with the printer’s temperature (400° F or 205° C).

Avoid using paper that has already been used in a printer or copier.

Do not print on both sides of envelopes, transparencies, or labels.

1-18 Printer Description

Paper Weight Equivalence Table

Use this table to determine approximate equivalent points in weight

specifications other than U.S. bond weight. For example, to determine

the equivalent of 20 lb U.S. bond weight paper in U.S. cover weight,

locate the bond weight (in the third row, first column) and scan across

the row to the cover weight (in the third column). The equivalent is

28 lb.

Shaded areas indicate a standard weight for that grade.

* U.S. postcard measurements are approximate. Use for reference only.

Table 1-15. Paper Weight Equivalence

Bond wt.

(17x22) Text/book

wt.

(25x38)

Cover wt.

(20x26) Bristol wt.

(22.5x

28.5)

Index wt.

(25.5x

30.5)

Tag wt.

(24x36) Metric wt. Bond wt.

(17x22) Text/book

wt.

(25x38)

Cover wt.

(20x26)

16# 41# 22# 27# 33# 37# 60 g/m216# 41# 22#

17# 43# 24# 29# 35# 39# 64 g/m217# 43# 24#

20# 50# * 28# 34# 42# 46# 75 g/m220# 50# * 28#

21# 54# 30# 36# 44# 49# 80 g/m221# 54# 30#

24# 60# * 33# 41# 50# 55# 90 g/m224# 60# * 33#

27# 68# 37# 45# 55# 61# 100 g/m227# 68# 37#

28# 70# * 39# 49# 58# 65# 105 g/m228# 70# * 39#

29# 74# 41# 50# 61# 68# 110 g/m229# 74# 41#

32# 80#* 44# 55# 67# 74# 120 g/m232# 80# * 44#

36# 90# 50# 62# 75# 83# 135 g/m236# 90# 50#

39# 100# 55# 67# 82# 91# 148 g/m239# 100# 55#

40# 101# 55# 68# 83# 92# 150 g/m240# 101# 55#

43# 110# 60# 74# 90# 100# 163 g/m243# 110# 60#

45# 115# 63# 77# 94# 104# 170 g/m245# 115# 63#

47# 119# 65# 80# 97# 108# 176 g/m247# 119# 65#

51# 128# 70# 86# 105# 117# 190 g/m251# 128# 70#

Paper Specifications 1-19

Labels

CAUTION To avoid damaging the printer, use only labels recommended for use

in laser printers.

If you have problems printing labels, use Tray 1 and open the Rear

Output Bin.

Never print on the same sheet of labels more than once.

Label Construction

When selecting labels, consider the quality of each component:

●Adhesives: The adhesive material should be stable at 400° F

(205° C), the printer’s maximum temperature.

●Arrangement: Only use labels with no exposed backing between

them. Labels can peel off of sheets that have spaces between the

labels, causing serious jams.

●Curl: Prior to printing, labels must lie flat with no more than 0.5 in

(13 mm) of curl in any direction.

●Condition: Do not use labels with wrinkles, bubbles, or other

indications of separation.

Transparencies

Transparencies used in the printer must be able to withstand 400° F

(205° C), the printer’s maximum temperature. For best results, close

the Rear Output Bin to print transparencies to the Top Output Bin.

CAUTION To avoid damaging the printer, use only transparencies recommended

for use in laser printers.

If you have problems printing transparencies, use Tray 1.

1-20 Printer Description

Envelopes

Envelope Construction

Envelope construction is critical. Envelope fold lines can vary

considerably, not only between manufacturers, but also within a box

from the same manufacturer. Successful printing on envelopes

depends upon the quality of the envelopes. When selecting

envelopes, consider the following components:

●Weight: The weight of the envelope paper should not exceed

28 lb (105 g/m2), or jamming may result.

●Construction: Prior to printing, envelopes should lie flat with less

than 0.25 in (6 mm) curl, and should not contain air. (Envelopes

that trap air may cause problems.)

●Condition: Make sure envelopes are not wrinkled, nicked, or

otherwise damaged.

●Sizes in Tray 1: From 3 by 5 in (76 by 127 mm) to 8.5 by 14 in

(216 by 356 mm).

●Sizes in the optional envelope feeder: From 3.5 by 6.3 in

(90 by 160 mm) to 7 by 10 in (178 by 254 mm).

If you do not have an optional envelope feeder, always print

envelopes from Tray 1. If envelopes wrinkle, try opening the Rear

Output Bin.

Paper Specifications 1-21

Envelopes with Double Side Seams

Some envelopes have vertical seams at both ends of the envelope,

rather than diagonal seams. This style of envelope may be more likely

to wrinkle. When using envelopes with double side seams, be sure

the seam extends all the way to the corner of the envelope as

illustrated below.

Figure 1-3 Envelopes with Double-Side-Seams

Envelopes with Adhesive Strips or Flaps

Envelopes with a peel-off adhesive strip or with more than one flap

that folds over to seal must use adhesives compatible with the heat

(400° F (205° C)) and pressure in the printer. The extra flaps and

strips might cause wrinkling, creasing, or jams.

Acceptable

Unacceptable

1-22 Printer Description

Envelope Margins

The following table gives typical address margins for a Commercial

#10 or DL envelope.

Note For the best print quality, position margins no closer than 0.6 in (15 mm)

from the edges of the envelope.

Envelope Storage

Proper storage of envelopes helps contribute to good print quality.

Envelopes should be stored flat. If air is trapped in an envelope,

creating an air bubble, then the envelope may wrinkle during printing.

Table 1-16. Envelope Margins

Type of Address Top Margin Left Margin

Return Address 0.6 in (15 mm) 0.6 in (15 mm)

Delivery Address 2 in (51 mm) 3.5 in (89 mm)

Paper Specifications 1-23

Card Stock and Heavy Paper

Many types of card stock can be printed from Tray 1, including index

cards and postcards. Some types of card stock perform better than

others because the construction is better suited for feeding through a

laser printer.

For optimum printer performance, do not use paper heavier than 53 lb

(199 g/m2) in Tray 1 or 28 lb (105 g/m2) in other trays. Paper that is

too heavy might cause misfeeds, stacking problems, paper jams, poor

Toner fusing, poor print quality, or excessive mechanical wear.

Note Printing on paper heavier than 53 lb may be possible if the tray is not

filled to capacity, and paper with a smoothness rating of 100-180

Sheffield is used.

Card Stock Construction

●Smoothness: 36-53 lb (135-199 g/m2) card stock should have a

smoothness rating of 100-180 Sheffield. 16-36 lb (60-135 g/m2)

card stock should have a smoothness rating of 100-250 Sheffield.

●Construction: Card stock should lie flat with less than 0.2 in

(5 mm) of curl.

●Condition: Make sure card stock is not wrinkled, nicked, or

otherwise damaged.

●Sizes: Use only card stock within the following size ranges:

• minimum: 3 by 5 in (76 by 127 mm)

• maximum: 8.5 by 14 in (216 by 356 cm)

Note Before loading card stock in Tray 1, make sure it is regular in shape

and not damaged. Also, make sure the cards are not stuck together.

Card Stock Guidelines

●If cards curl or jam, try printing from Tray 1 and opening the Rear

Output Bin.

●Set margins at least 0.08 in (2 mm) away from the edges of the

paper.

1-24 Printer Description

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 August 1, 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.

WARNING! Using controls, making adjustments, or performing procedures other

than those specified in this service manual may result in exposure to

hazardous radiation.

Canadian DOC Regulations

Complies with Canadian EMC Class B requirements.

«Conforme á la classe B des normes canadiennes de compatibilité

électromagnétiques. «CEM».»

Safety Information 1-25

FCC Regulations

This equipment has been tested and found to comply with the limits

for a Class B digital device, pursuant to Part 15 of the FCC rules.

These limits are designed to provide reasonable protection against

harmful interference in a residential installation. This equipment

generates, uses, and can radiate radio frequency energy. If this

equipment is not installed and used in accordance with the

instructions, it may cause harmful interference to radio

communications. However, there is no guarantee that interference will

not occur in a particular installation. If this equipment does cause

harmful interference to radio or television reception, which can be

determined by turning the equipment off and on, the user is

encouraged to try to correct the interference by one or more of the

following measures:

●Reorient or relocate the receiving antenna.

●Increase separation between equipment and receiver.

●Connect equipment to an outlet on a circuit different from that to

which the receiver is located.

●Consult your dealer or an experienced radio/TV technician.

Note Any changes or modifications to the printer that are not expressly

approved by HP could void the user’s authority to operate this

equipment.

Use of a shielded interface cable is required to comply with the Class B

limits of Part 15 of FCC rules.

1-26 Printer Description

Laser Statement for Finland

LASERTURVALLISUUS

LUOKAN 1 LASERLAITE

KLASS 1 LASER APPARAT

HP LaserJet 4000/4000 T/4000 N/4000 TN and

4050/4050 T/4050 N/4050 TN -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

(1993) 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 4000/4000 T/4000 N/4000 TN and

4050/4050 T/4050 N/4050 TN -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

Safety Information 1-27

Toner Safety

Note Toner may stain clothing. 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 melt and permanently fuse

into clothing.

The Toner Cartridge/Drum Material Safety Data Sheet (MSDS) can

be obtained by contacting the HP LaserJet website at:

http://www.ljsupplies.com/planetpartners/datasheets.html.

If you do not have access to the Internet, call the U.S. HP FIRST

fax-on-demand service at (800) 231-9300. Use index number 7 for a

listing of the Toner Cartridge/Drum Material/Chemical Safety Data

Sheets.

Note To get documents from HP FIRST by fax, you must use a Group 3 fax

machine.

1-28 Printer Description

Environmental Product Stewardship

Protecting the Environment

Hewlett-Packard Company is committed to providing quality products

in an environmentally-sound manner. The printer has been designed

to minimize impacts on the environment.

The printer design eliminates:

Ozone

Production The printer uses charging rollers in the electrophotographic process and

therefore generates no appreciable ozone gas (03).

CFC Usage Class I U.S. Clean Air Act stratospheric ozone-depleting chemicals

(chlorofluorocarbons [CFCs], for example) have been eliminated from the

manufacturing of the printer and packaging.

The printer design reduces:

Energy

Consumption Energy usage drops from 330 watts (W) during printing to as little as 20W

while in low-power (PowerSave) mode. This saves energy without affecting

the high performance of the printer. This product qualifies for the

ENERGY STAR® Program (U.S. and Japan). ENERGY STAR is a voluntary

program established to encourage the development of energy-efficient

office products. The ENERGY STAR name is a registered service mark of the

U.S. Environmental Protection Agency.

As an ENERGY STAR partner, Hewlett-Packard

Company has determined that this product meets

ENERGY STAR Guidelines for energy efficiency.

Overview 2-1

2Service Approach

Overview

This chapter discusses the following:

●Service Approach

●Parts and Supplies

●Warranty Statement

2-2 Service Approach

Service Approach

Repair of the printer normally begins with use of the printer’s internal

diagnostics in conjunction with the troubleshooting procedures in

Chapter 7. Once a faulty part is located, repair is generally

accomplished by assembly level replacement of Field Replaceable

Units (FRUs). Some mechanical assemblies may be repaired at the

subassembly level. PCA component replacement is not supported by

Hewlett-Packard.

Parts and Supplies 2-3

Parts and Supplies

Ordering Information

Field replaceable and accessory part numbers are found in Chapter 8

of this manual. Replacement parts may be ordered from HP’s Service

Materials Organization (SMO) or Support Materials Europe (SME),

divisions of Product Support Division (PSD).

Use only accessories specifically designed for this printer.

Accessories can be ordered from an authorized service or support

provider. See page 2-6 and page 8-4 for ordering information.

2-4 Service Approach

Helpful Documentation

Table 2-1 lists part numbers to order documentation.

Table 2-1. Helpful Documentation

Item Description or Use Part Number

HP LaserJet Printer Family

Paper Specification Guide

A guide to using paper and other

print media with HP LaserJet

printers.

5040-9072

PCL 5/PJL Technical Reference

Documentation Package

A guide to using printer

commands with HP LaserJet

printers.

5021-0330

HP LaserJet Basics

CD-ROM A guide to using HP LaserJet

printer hardware 5081-9469

User’s Documentation Bundle,

HP LaserJet 4000 and 4000 N

Printers

An additional copy of the user’s

guide, the getting started guide,

and the quick reference guide.

C4118-99051

(English)

User’s Documentation Bundle,

HP LaserJet 4000 T and

4000 TN Printers

An additional copy of the user’s

guide, the getting started guide,

and the quick reference guide.

C4119-99047

(English)

HP LaserJet 4050, 4050 T,

4050 N, and 4050 TN User’s

Documentation CD-ROM

An additional copy of the user’s

documentation CD-ROM C4251-60104

User’s Documentation Bundle,

HP LaserJet 4050 and 4050 N

Printers

An additional copy of the getting

started guide, and the quick

reference guide.

C4251-99001

(English)

User’s Documentation Bundle,

HP LaserJet 4050 T and

4050 TN

An additional copy of the getting

started guide, and the quick

reference guide.

C4252-99001

(English)

Parts and Supplies2-5

Service and Support CD-ROM

for the

HPLaserJet 4050 Printers

An interactive training CD-ROM

for printer service

representatives and customer

care specialists.

C4251-60106

HP LaserJet 4000 and 4050

Series Printers Service Manual A combined service manual for

both series of printers.C4251-91003

Table 2-1.Helpful Documentation (continued)

Item Description or Use Part Number

2-6 Service Approach

Phone Numbers for Ordering

●SMO (Service Materials Organization)

1-800-227-8164 (U.S. only)

●SME (Support Materials Europe)

(49 7031) 142253

Exchange Program

HP offers remanufactured assemblies for some parts. These are

identified in Chapter 8 and can be ordered through Service Materials

Organization (SMO) or Support Materials Europe (SME), divisions of

Product Support Division (PSD).

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 may 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 accessed via the

World Wide Web at http://www.hp.com/go/partsinfo.

Parts and Supplies 2-7

HP Support Assistant Compact Disc

This support tool offers a comprehensive online information system

designed to provide technical and product information on 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.

HP FIRST

HP FIRST fax-on-demand service will deliver detailed troubleshooting

information on common software and troubleshooting tips for your HP

product. Call from any touch tone phone and request up to three

documents per call. These documents will be sent to the fax of your

choice. Many of these numbers are local numbers and will not work

internationally.

North and Latin America

Outside the U.S. and Canada: (404) 329-2009

In the U.S and Canada: (800) 333-1917

Asia/Pacific

Australia (03) 9272 2627

China (10) 6505 5280

Hong Kong 2506 2422

India (11) 682 6031

Indonesia (21) 352 2044

Japan (03) 3335 8622

Korea (02) 769 0543

Malaysia (03) 298 2478

New Zealand (09) 356 6648

Philippines (02) 848 9880

Singapore 275 7251

Thailand (02) 661 3511

Vietnam (08) 823 4161

2-8 Service Approach

Europe, Middle East, and Africa

Austria 0660-8218

Belgium

Dutch 0800 1 1906

French 0800 1 7043

Denmark 800-10453

European International +31 20 681 5792

Finland 9800-13134

France 0800-9050900

Germany 0130-810061

Hungary 36 1 461-8222

Italy 1678-59020

Netherlands 0800-0222420

Norway 800-11319

Portugal 05 05 313342

Spain 900-993123

Sweden 020-795743

Switzerland

French 0800-551526

German 0800-551527

United Kingdom 0800-960271

Customer Care Reseller Sales and Service Support

Center

The Customer Care Reseller Sales and Service Support Center is

available to assist resellers and service technicians. You can reach

this support center at 1-800-544-9976.

Other Areas

Outside of North America and Europe, contact your local HP sales

office for assistance in obtaining technical support for resellers and

service technicians.

Parts and Supplies 2-9

Toner Cartridge Information

The Toner Cartridge is designed to simplify replacement of the major

“consumable” parts. The Toner Cartridge contains the printing

mechanism and a supply of Toner.

At 5% page coverage, a Toner Cartridge will print approximately

6,000 or 10,000 pages (depending on the model installed). However,

a Toner Cartridge should print more pages if regularly printing pages

with less coverage, such as short memos. If EconoMode is used

full-time, it is possible that the Toner supply will outlast the mechanical

parts in the Toner Cartridge. The cartridge may print fewer pages if

routinely printing dense print.

Note For best results, always use a Toner Cartridge before the expiration

date stamped on the Toner Cartridge’s box.

Refilled Toner Cartridges

While Hewlett-Packard does not prohibit the use of refilled Toner

Cartridges during the warranty period or while the printer is under a

maintenance contract, it is not recommended for the following

reasons:

●Repairs resulting from the use of refilled Toner Cartridges are not

covered under Hewlett-Packard warranty or maintenance

contracts.

●Hewlett-Packard has no control or process to ensure that a

refilled Toner Cartridge functions at the high level of reliability of a

new HP LaserJet Toner cartridge. Hewlett-Packard also cannot

predict what the long term reliability effect on the printer is from

using different Toner formulations found in refilled cartridges.

●The print quality of HP LaserJet Toner Cartridges influences the

customer’s perception of the printer. Hewlett-Packard has no

control over the actual print quality of a refilled Toner Cartridge.

Recycling Toner Cartridges

In order to reduce waste, Hewlett-Packard offers a recycling program

for used Toner Cartridges. Cartridge components that do not wear out

are recycled. Plastics and other materials are recycled. HP pays the

shipping costs from the user to the recycling plant. For each cartridge

returned, HP donates one U.S. dollar to be shared by the Nature

Conservancy and the National Wildlife Federation. To join this

recycling effort, follow the instructions inside the Toner Cartridge’s

box.

2-10 Service Approach

Warranty Statement

The warranty for this product gives you specific legal rights. There

may also be other rights that vary from area to area. Refer to the

user’s documentation for the full warranty and supporting warranty

information.

Overview 3-1

3Printer Operation

Overview

This chapter discusses the following:

●Using the Control Panel

●Control Panel Menus

●Service Mode

●Testing the Printer

●Resetting the Printer

●System Configuration

●Printer I/O Configuration

3-2 Printer Operation

Using the Control Panel

Control Panel Layout

The printer’s Control Panel consists of the following:

Figure 3-1 Control Panel Layout

Control Panel Lights

Ready

Data

Attention

Item

– Value +

Select

Cancel

Job

2-line

display

READY

4050

only

Table 3-1. Control Panel Lights

Light Indication

Ready The printer is ready to print.

Data The printer is processing information.

Attention Action is required. See the Control Panel display.

Using the Control Panel 3-3

Control Panel Keys

Table 3-2. Control Panel Keys

Key Function

[Go] ●Places the printer either online or offline.

●Prints any data residing in the printer’s buffer.

●Allows the printer to resume printing after being offline. Clears

most printer messages and places the printer online.

●Allows the printer to continue printing with an error message

such as TRAY X LOAD [TYPE] [SIZE] or UNEXPECTED

PAPER SIZE.

●Confirms a manual feed request if Tray 1 is loaded and

TRAY 1 MODE=CASSETTE has been set from the Paper

Handling Menu in the printer’s Control Panel.

●Overrides a manual feed request from Tray 1 by selecting

paper from the next available tray.

●Exits the Control Panel menus. (To save a selected Control

Panel setting, first press [Select].)

[Cancel Job] Cancels the print job that the printer is processing. The time it

takes to cancel depends on the size of the print job. (Press it only

once.)

[Menu] Cycles through the Control Panel menus. Press the right end of

the button to move forward or the left end of the button to move

backward.

[Item] Cycles through the selected menu’s items. Press the right end of

the button to move forward or the left end of the button to move

backward.

[– Value +] Cycles through the selected menu item’s values. Press [+] to

move forward or [–] to move backward.

[Select] ●Saves the selected value for that item. An asterisk (*) appears

next to the selection, indicating that it is the new default.

Default settings remain when the printer is switched off or

reset (unless you reset all factory defaults from the Resets

Menu).

●Prints one of the printer information pages from the Control

Panel.

[?] Provides instructions for resolving most printer errors. Certain

Control Panel error messages alternate with instructions on

accessing the online help system. This on-board help system is a

feature of the 4050 series printer only.

3-4 Printer Operation

Settings and Defaults

The printer makes most printing decisions based on either temporary

settings or permanent defaults.

Note Settings sent from software applications override printer defaults.

Setting the display language

1Press and hold [Select] while turning on the printer. Hold

[Select] until SELECT LANGUAGE appears.

2Release [Select]. INITIALIZING appears briefly. Wait for

LANGUAGE=ENGLISH to appear.

3Press [– Value +] repeatedly until the desired language appears.

4Press [Select] to save your choice. An asterisk (*) will appear

beside the selected language.

5Press [Go] to exit the menu.

Table 3-3. Settings and Defaults

Setting or Default Explanation

Temporary Setting A value set for the current print job by the software application. For

example, a request from the software to print three copies instead

of the Control Panel default value of one copy is a temporary

setting. The printer continues to use the temporary setting until it

receives another software request or until it is reset.

Control Panel Default A value set at the Control Panel when you select a menu item. An

asterisk appears, indicating the default setting. The printer retains

this default when it is turned off.

Factory Default The value set for each menu item at the factory. Factory defaults

are listed in the item column in the menu tables starting on

page 3-8.

Control Panel Menus 3-5

Control Panel Menus

Press [Menu] for access to all Control Panel menus. When additional

trays or other accessories are installed in the printer, new menu items

automatically appear.

To change a Control Panel setting:

1Press [Menu] until the desired menu appears.

2Press [Item] until the desired item appears.

3Press [– Value +] until the desired setting appears.

4Press [Select] to save the selection. An asterisk (*) appears next

to the selection in the display, indicating that it is now the default.

5Press [Go] to exit the menu.

Note Settings in the printer driver and software application override Control

Panel settings. (Software application settings override printer driver

settings.)

If you cannot access a menu or item, it is either not an option for the

printer, or the customer’s network administrator has locked the function.

(The Control Panel reads ACCESS DENIED MENUS LOCKED.) See the

customer’s network administrator.

To print a Control Panel menu map:

To see the current settings for all of the menus and menu items

available on the Control Panel, print a Control Panel menu map.

1Press [Menu] until INFORMATION MENU appears.

2Press [Item] until PRINT MENU MAP appears.

3Press [Select] to print the menu map.

3-6 Printer Operation

Quick Copy Jobs Menu

This menu provides a list of the quick copy jobs stored on the printer’s

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 3-4. Quick Copy Jobs Menu

Item Value Explanation

[JOBNAME] The name of the person who owns the quick copy

job.

COPIES=1 1 to 999

DELETE

The number of additional 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.

Control Panel Menus 3-7

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 3-5. Private/Stored Jobs Menu

Item Value Explanation

[JOBNAME] The name of the job stored on the printer’s hard

disk.

PIN:0000 To print the job, the user must enter the Personal

Identification Number (PIN) 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.

3-8 Printer Operation

Information Menu

This menu contains printer information pages that give details about

the printer and its configuration. To print an information page, scroll to

the desired page and press [Select].

Table 3-6. Information Menu

Item Explanation

MENU MAP

The menu map shows the layout and current settings of the

Control Panel menu items.

CONFIGURATION

The Configuration Page shows the printer’s current configuration.

If an HP JetDirect print server card is installed (HP LaserJet

4000 N/4000 TN and 4050 N/4050 TN printers), a JetDirect

Configuration Page will print out as well.

PCL FONT LIST

The PCL font list shows all the PCL fonts currently available to the

printer.

PS FONT LIST

The PS font list shows all the PS fonts currently available to the

printer.

FILE DIRECTORY

This item appears only when a mass storage device (such as an

optional flash DIMM or hard disk) containing a recognized file

system is installed in the printer. The file directory shows

information for all installed mass storage devices.

EVENT LOG

The event log lists printer events or errors.

SHOW

EVENT LOG

This item allows you to view the most recent printer events on the

Control Panel display. Press [– Value +] to scroll through the

event log entries.

PAPER PATH TEST

The paper path test can be used to verify that the paper path is

working properly, or to troubleshoot problems with a type of paper.

Choose the input tray, output bin, duplexer (if available), and

number of copies.

USAGE PAGE

The usage page shows the quantity of pages printed, as well as

the paper size used. It also reflects the number of one-sided

versus two-sided pages (HP LaserJet 4050 only, with hard disk

installed).

Control Panel Menus 3-9

Paper Handling Menu

When paper handling settings are correctly configured through the

Control Panel, you can print by choosing the type and size of paper

from the printer driver or software application.

Some items in this menu (such as duplex and manual feed) can be

accessed from a software application, or from the printer driver (if the

appropriate driver is installed). Printer driver and software application

settings override Control Panel settings.

Table 3-7. Paper Handling Menu

Item Values Explanation

ENVELOPE FEEDER

SIZE=COM10

For supported paper sizes

see page 1-12. This item appears only when the

optional envelope feeder is installed.

Set the value to correspond with the

envelope size currently loaded in the

envelope feeder.

ENVELOPE FEEDER

TYPE=PLAIN

For supported paper types

see page 1-12. This item appears only when the

optional envelope feeder is installed.

Set the value to correspond with the

envelope type currently loaded in the

envelope feeder.

TRAY 1 MODE=

FIRST

CASSETTE

Determine how the printer will use

Tray 1.

FIRST: If paper is loaded in Tray 1,

the printer will pull paper from that

tray first.

CASSETTE: A paper size must be

assigned to Tray 1 using the

TRAY 1 SIZE option (the next item

in this menu when TRAY 1

MODE=CASSETTE). This allows Tray 1

to be used as a reserved tray.

TRAY 1 SIZE=

LETTER

For supported paper sizes

see page 1-12. This item appears only when TRAY 1

MODE= CASSETTE. Set the value to

correspond with the paper size

currently loaded in Tray 1.

3-10 Printer Operation

TRAY 1 TYPE=

PLAIN

For supported paper types

see page 1-12. This item appears only when TRAY 1

MODE= CASSETTE. Set the value to

correspond with the paper type

currently loaded in Tray 1.

TRAY 2 TYPE=

PLAIN

For supported paper types

see page 1-12. Set the value to correspond with the

paper type currently loaded in Tray 2.

TRAY 3 TYPE=

PLAIN

For supported paper types

see page 1-12. This item appears only when a third

paper tray is installed. Set the value

to correspond with the paper type

currently loaded in Tray 3.

TRAY 4 TYPE=

PLAIN

For supported paper types

see page 1-12. This item appears only when a fourth

paper tray is installed (available only

on the HP LaserJet 4000 T/4000 TN

and 4050 T/4050 TN printers). Set

the value to correspond with the

paper type currently loaded in Tray 4.

MANUAL FEED=OFF OFF

Feed the paper manually from Tray 1,

rather than automatically from a tray.

When MANUAL FEED=ON and Tray 1

is empty, the printer goes offline when

it receives a print job and displays

MANUALLY FEED [PAPER SIZE].

DUPLEX=OFF OFF

This item appears only when an

optional duplexer is installed. Set the

value to ON to print on both sides

(duplex) or OFF to print on one side

(simplex) of a sheet of paper.

BINDING=

LONG EDGE

SHORT EDGE

This item appears only when an

optional duplexer is installed and the

duplex option is on. Choose the

binding edge when duplexing

(printing on both sides of paper).

Table 3-7. Paper Handling Menu (continued)

Item Values Explanation

Control Panel Menus 3-11

OVERRIDE A4/

LETTER=NO

YES

Choose YES to print on letter size

paper when an A4 job is sent, but no

A4 size paper is loaded in the printer

(or to print on A4 size paper when a

letter job is sent, but no letter paper is

loaded in the printer).

CONFIGURE FUSER

MODE MENU=NO

YES

Configure the Fuser mode associated

with each paper type. (This is only

necessary if you are experiencing

problems printing on certain paper

types.)

NO: The Fuser mode menu items are

not accessible.

YES: Additional items appear (see

below).

Note

To see the default Fuser mode for

each paper type, select YES, scroll

back to the Information Menu, and

print a menu map (page 3-8).

[TYPE]=

NORMAL

LOW

HIGH

This item appears only when

CONFIGURE FUSER MODE

MENU=YES. Most paper types are set

to NORMAL by default.

The exception is as follows:

ROUGH=HIGH

(The ROUGH=HIGH setting is only

available with A4, letter, and legal

sizes.)

For a complete list of supported paper

types, see page 1-12.

Table 3-7. Paper Handling Menu (continued)

Item Values Explanation

3-12 Printer Operation

Print Quality Menu

Some items in this menu can be accessed from a software

application, or from the printer driver (if the appropriate driver is

installed). Printer driver and software application settings override

Control Panel settings.

Table 3-8. Print Quality Menu

Item Values Explanation

RESOLUTION=

FASTRES 1200

300

600

FASTRES 1200

PRORES 1200

Select the resolution from the

following values:

300: Produces draft print quality at

the printer’s maximum speed (17

ppm). 300 dpi (dots per inch) is

recommended for some

bitmapped fonts and graphics, and

for compatibility with the HP

LaserJet III family of printers.

600: Produces high print quality at

the printer’s maximum speed

(17 ppm).

FASTRES 1200: Produces

optimum print quality (comparable

to 1200 dpi) at the printer’s

maximum speed (17 ppm).

PRORES 1200: Produces optimum

print quality (true 1200 dpi) at half

the printer’s maximum speed (8

ppm for the HP LaserJet 4000

printer, or at highest print quality at

engine speed for the HP LaserJet

4050 printer).

When the resolution is changed,

any downloaded resources (such

as fonts or macros) will need to be

downloaded again, unless they are

stored on an optional hard disk or

flash DIMM.

Note

It is best to change the resolution

from the printer driver or software

application. (Driver and software

settings override Control Panel

settings.)

Control Panel Menus 3-13

RET=MEDIUM OFF

LIGHT

MEDIUM

DARK

Use the printer’s Resolution

Enhancement technology (REt)

setting to produce print with

smooth angles, curves, and

edges.

REt does not affect print quality

when the print resolution is set to

ProRes 1200. All other print

resolutions, including

FastRes 1200, benefit from REt.

Note

It is best to change the REt setting

from the printer driver or software

application. (Driver and software

settings override Control Panel

settings.)

ECONOMODE=OFF OFF

Turn EconoMode on (to save

Toner) or off (for high quality).

EconoMode creates draft-quality

printing by reducing the amount of

Toner on the printed page by up

to 50%.

Caution

HP does not recommend full-time

use of EconoMode. (If

EconoMode is used full-time, it is

possible that the Toner supply will

outlast the mechanical parts in the

Toner cartridge.)

Note

It is best to turn EconoMode on or

off from the printer driver or

software application. (Driver and

software settings override Control

Panel settings.)

Table 3-8. Print Quality Menu (continued)

Item Values Explanation

3-14 Printer Operation

TONER DENSITY=3 1

Lighten or darken the print on the

page by changing the Toner

density setting. The settings range

from 1 (light) to 5 (dark), but the

default setting of 3 usually

produces the best results.

Use a lower Toner density setting

to save Toner.

Note

It is best to change the Toner

density from the printer driver or

software application. (Driver and

software settings override Control

Panel settings.)

CREATE

CLEANING PAGE

No value to select. Press [Select] to print a cleaning

page (for cleaning excess Toner

from the Fuser assembly).

In order for the cleaning page to

work properly, print the page on

copier grade paper (not bond or

rough paper). Follow the

instructions on the cleaning page.

PROCESS

CLEANING PAGE

No value to select. This item appears only after a

cleaning page has been

generated (as described above).

Press [Select] to process the

cleaning page.

Table 3-8. Print Quality Menu (continued)

Item Values Explanation

Control Panel Menus 3-15

Printing Menu

Some items in this menu can be accessed from a software

application, or from the printer driver (if the appropriate driver is

installed). Printer driver and software application settings override

Control Panel settings.

Table 3-9. Printing Menu

Item Values Explanation

COPIES=1 1 TO 999 Set the default number of

copies by selecting any

number from 1 to 999. Press

[– Value +] once to change the

setting by increments of 1, or

hold down [– Value +] to scroll

by increments of 10.

Note

It is best to set the number of

copies from the printer driver or

software application. (Driver

and software settings override

Control Panel settings.)

PAPER=

LETTER

(110V printers)

PAPER=

(220V printers)

and

ENVELOPE=

COM10

(110V printers)

ENVELOPE=

(220V printers)

For supported paper sizes see

page 1-12. Set the default image size for

paper and envelopes. (The

item name will change from

paper to envelope as you scroll

through the available sizes.)

CONFIGURE CUSTOM

PAPER=NO

YES

NO: The custom paper menu

items are not accessible.

YES: The custom paper menu

items appear (see the next

item).

3-16 Printer Operation

UNIT OF MEASURE=

INCHES

(110V printers)

MILLIMETERS

(220V printers)

INCHES

MILLIMETERS

This item appears only when

CONFIGURE CUSTOM

PAPER=YES. Select the unit of

measurement for the custom

paper size.

X DIMENSION=

8.5 INCHES

(110V printers)

216 MILLIMETERS

(220V printers)

3.00 TO 8.5 INCHES

(110V printers)

76 to 216 MILLIMETERS

(220V printers)

This item appears only when

CONFIGURE CUSTOM

PAPER=YES. Select the

dimension to be fed into the

printer (short edge).

Y DIMENSION=

14.0 INCHES

(110V printers)

356 MILLIMETERS

(220V printers)

5.00 TO 14.0 INCHES

(110V printers)

127 to 356 MILLIMETERS

(220V printers)

This item appears only when

CONFIGURE CUSTOM

PAPER=YES. Select the other

dimension (long edge).

FORM=

60 LINES

(110V printers)

64 LINES

(220V printers)

5 to 128 Sets vertical spacing from 5 to

128 lines for default paper size.

Press [– Value +] once to

change the setting by

increments of 1, or hold down

[– Value +] to scroll by

increments of 10.

ORIENTATION=

PORTRAIT

LANDSCAPE

Determine the default

orientation of print on the page.

Note

It is best to set the page

orientation from the printer

driver or software application.

(Driver and software settings

override Control Panel

settings.)

Table 3-9. Printing Menu (continued)

Item Values Explanation

Control Panel Menus 3-17

PCL FONT

SOURCE=INTERNAL

INTERNAL

SOFT

SLOT 1, 2, OR 3

INTERNAL: Internal fonts.

SOFT: Permanent soft fonts.

SLOT 1, 2, or 3: Fonts stored

in one of the three DIMM slots.

Note

It is best to set the font source

from the printer driver or

software application. (Driver

and software settings override

Control Panel settings.)

PCL FONT

NUMBER=0

0 TO 999 The printer assigns a number

to each font and lists them on

the PCL Font List. The font

number appears in the Font #

column of the printout.

Note

It is best to set the font number

from the printer driver or

software application. (Driver

and software settings override

Control Panel settings.)

PCL FONT

PITCH= 12.00

0.44 TO 99.99 This item might not appear,

depending on the font

selected. Press [– Value +]

once to change setting by

increments of.01 for pitch, or

hold down [– Value +] to scroll

by increments of 1.

Note

It is best to set the font pitch

from the printer driver or

software application. (Driver

and software settings override

Control Panel settings.)

Table 3-9. Printing Menu (continued)

Item Values Explanation

3-18 Printer Operation

PCL SYMBOL

SET=PC-8

PC-8

many others Select any one of several

available symbol sets from the

printer’s Control Panel. A

symbol set is a unique

grouping of all the characters in

a font. PC-8 or PC-850 is

recommended for line draw

characters.

Note

It is best to set the symbol set

from the printer driver or

software application. (Driver

and software settings override

Control Panel settings.)

COURIER=REGULAR REGULAR

DARK

Select the version of Courier

font to use:

REGULAR: The internal

Courier font available on the

HP LaserJet 4 series printers.

DARK: The internal Courier font

available on the HP LaserJet III

series printers.

Both fonts are not available at

the same time.

WIDE A4=NO NO

YES

The Wide A4 setting changes

the number of characters that

can be printed on a single line

of A4 paper.

NO: Up to 78 10-pitch

characters can be printed on

one line.

YES: Up to 80 10-pitch

characters can be printed on

one line.

Table 3-9. Printing Menu (continued)

Item Values Explanation

Control Panel Menus 3-19

APPEND CR TO LF=

YES

Select YES to append a

carriage return to each line

feed encountered in

backward-compatible PCL

jobs (pure text, no job control).

Some environments, such as

UNIX, indicate a new line using

only the line feed control code.

This option allows the user to

append the required carriage

return to each line feed.

PRINT PS ERRORS=OFF OFF

Select ON to print the PS error

page when PS errors occur.

Table 3-9. Printing Menu (continued)

Item Values Explanation

3-20 Printer Operation

Configuration Menu

Items in this menu affect the printer’s behavior. Configure the printer

according to your printing needs.

Table 3-10. Configuration Menu

Item Values Explanation

POWERSAVE=

30 MINUTES

OFF

15 MINUTES

30 MINUTES

1 HOUR

2 HOURS

3 HOURS

Set the printer to enter PowerSave after it

has been idle for a specified amount of time.

Turning PowerSave off is not

recommended. The PowerSave feature

does the following:

1. Minimizes the amount of power

consumed by the printer when it is idle.

2. Reduces wear on the printer’s electronic

components. (Turns off the display’s

backlight.)

When you send a print job, press a Control

Panel key, open a paper tray, or open the

top cover, the printer automatically comes

out of PowerSave mode.

Note

PowerSave turns off the backlight on the

display, but the display is still readable.

PERSONALITY=

AUTO

PCL

Select the default printer language

(personality). Possible values are

determined by which valid languages are

installed in the printer.

Normally you should not change the printer

language (the default is AUTO). If you

change it to a specific printer language, the

printer will not automatically switch from one

language to another unless specific

software commands are sent to the printer.

Control Panel Menus 3-21

RESOURCE SAVE=

OFF

AUTO

Dedicate printer memory to save each

language’s permanent resources. (You

might need to add memory to the printer in

order for this item to appear.) The amount of

memory set aside can be different for each

installed language. Some languages might

have memory set aside for resource saving

without requiring all languages to do so. Any

time the amount of memory dedicated to a

specific language is changed, all languages

will lose all saved resources, including any

unprocessed print jobs.

OFF: No language resource saving is

performed, and language-dependent

resources, such as fonts and macros, are

lost when language or resolution changes.

ON: An item will appear for each installed

language that allows the user to allocate a

particular amount of memory to that

language’s resource saving area. (See the

items below.)

AUTO: The printer automatically determines

the amount of memory to use for each

installed language’s resource saving area.

PCL MEMORY=

400K

0K and up

(This value depends on

the amount of installed

memory.)

This item appears only when RESOURCE

SAVE=ON. Select the amount of memory

used for saving PCL resources. Printer

default is the minimum amount of memory

needed to perform resource saving for PCL.

Press [– Value +] to change settings by

increments of 10 (up to 100 KB) or by

increments of 100 (above 100 KB).

PS MEMORY=

400K

0K and up

(This value depends on

the amount of installed

memory.)

This item appears only when RESOURCE

SAVE=ON. Select the amount of memory

used for saving PS resources. Printer

default is the minimum amount of memory

needed to perform resource saving for PS.

Press [– Value +] to change settings by

increments of 10 (up to 100 KB) or by

increments of 100 (above 100 KB).

Table 3-10. Configuration Menu (continued)

Item Values Explanation

3-22 Printer Operation

PAGE PROTECT=

AUTO

This item appears only after a 21 PAGE

TOO COMPLEX, PRESS GO TO

CONTINUE message displays.

Memory Enhancement technology (MEt)

attempts to guarantee that all pages will

print. If the page does not print, turn PAGE

PROTECT to ON. This might increase

chances of a 20 INSUFFICIENT

MEMORY, PRESS GO TO CONTINUE

message. If this occurs, simplify the print

job or install additional memory.

CLEARABLE

WARNINGS=JOB

JOB

Set the amount of time that a clearable

warning is displayed on the printer’s Control

Panel.

JOB: Warning messages display on the

Control Panel until the end of the job from

which they were generated.

ON: Warning messages display on the

Control Panel until [Go] is pressed.

AUTO CONTINUE=

OFF

Determine how the printer reacts to errors.

ON: If an error occurs that prevents printing,

the message will display, and the printer will

go offline for 10 seconds before returning

online.

OFF: If an error occurs that prevents

printing, the message will remain on the

display and the printer will remain offline

until [Go] is pressed.

If the printer is on a network, you will

probably want to turn AUTO CONTINUE to

ON.

Table 3-10. Configuration Menu (continued)

Item Values Explanation

Control Panel Menus 3-23

TONER

LOW=CONTINUE

CONTINUE

STOP

Determine how the printer behaves when

Toner is low. The TONER LOW message will

first appear when the Toner Cartridge is

almost out of Toner. (About 100 to 300

sheets can still be printed.)

CONTINUE: The printer will continue to print

while the TONER LOW message is

displayed.

STOP: The printer will go offline and wait for

further action.

RAM DISK=OFF OFF

AUTO

Determine how the RAM disk is configured.

This item appears only if there is no optional

hard disk installed and the printer has at

least 8 MB of memory.

OFF: The RAM disk is disabled.

ON: The RAM disk is enabled. Configure the

amount of memory to be used through the

following item: RAM DISK SIZE.

Note

If the setting is changed from OFF to ON or

from OFF to AUTO, the printer will

automatically reinitialize when it becomes

idle.

RAM DISK

SIZE=XXXK

0K and up

(This value depends on

the amount of installed

memory.)

Determine the size of the RAM disk. This

item appears if RAM DISK=ON or AUTO.

Press [– Value +] to change settings by

increments of 100.

Note

This setting cannot be changed if RAM

DISK=AUTO. Changing this value will cause

the printer to reinitialize when it becomes

idle.

Table 3-10. Configuration Menu (continued)

Item Values Explanation

3-24 Printer Operation

JAM RECOVERY=

AUTO

OFF

Determine how the printer behaves when a

paper jam occurs.

AUTO: The printer automatically selects the

best mode for printer jam recovery (usually

AUTO). This is the default setting.

ON: The printer automatically reprints pages

after a paper jam is cleared.

OFF: The printer does not reprint pages

following a paper jam. Printing performance

might be increased with this setting.

MAINTENANCE

MESSAGE=OFF

OFF This item appears only after the PERFORM

PRINTER MAINTENANCE message

displays.

OFF: The PERFORM PRINTER

MAINTENANCE message will be cleared and

will not be displayed again until the next

maintenance is due.

The message should not be turned off

unless the printer maintenance has been

performed. If the required maintenance is

not performed, the printer’s performance will

degrade.

SMALL PAPER

SPEED=NORMAL

NORMAL

SLOW

Select SLOW when alternately printing

envelopes or small paper and standard

paper sizes.

Be sure to return the speed to NORMAL

when finished.

TONER LOW=CONTINUE CONTINUE

STOP

Determine how the printer behaves when

Toner is low. The TONER LOW message

will first appear when the Toner Cartridge is

almost out of Toner. (About 100 to 300

sheets can still be printed)

CONTINUE: The printer will continue to print

while the TONER LOW message is

displayed.

STOP: The printer will go offline and wait for

further action.

Table 3-10. Configuration Menu (continued)

Item Values Explanation

Control Panel Menus 3-25

QUICK COPY

JOBS = 32

(HP LaserJet 4050

series printer with hard

disk installed only)

1 to 50 Specifies the number of quick copy jobs that

can be stored on the printer’s hard disk.

HELD JOB

TIMEOUT = OFF

(HP LaserJet 4050

series printer with hard

disk installed only)

1 HOUR

4 HOURS

1 DAY

1 WEEK

This setting allows the user to set the

timeout value for how long a job will be

stored before it is automatically deleted

from the held job queue.

CONFIGURE

PRORES 1200=NO*

(HP LaserJet 4050

series printer only)

YES

This item allows the user to tell the printer

whether or not to use ProRes, which

provides 1200 dpi. If YES is selected,

another menu entry appears giving the user

the option of NORMAL or HALF speed.

Table 3-10. Configuration Menu (continued)

Item Values Explanation

3-26 Printer Operation

I/O Menu

Items in the I/O (input/output) Menu affect the communication

between the printer and the computer.

Table 3-11. I/O Menu

Item Values Explanation

I/O TIMEOUT=15 5 to 300 Select the I/O timeout period in seconds. (I/O

timeout refers to the time, measured in seconds,

that the printer waits before ending a print job.)

This setting allows you to adjust timeout for best

performance. If data from other ports appear in

the middle of your print job, increase the timeout

value.

Press [– Value +] once to change settings by

increments of 1, or hold down [– Value +] to

scroll by increments of 10.

I/O BUFFER=AUTO AUTO

OFF

Allocate memory for I/O buffering.

AUTO: The printer automatically reserves

memory for I/O buffering. Additional

configurations are not required and the

I/O BUFFER SIZE menu item does not

appear.

ON: The I/O BUFFER SIZE item appears (see

below). Specify the amount of memory to be

used for I/O buffering.

OFF: I/O buffering is not performed and the

I/O BUFFER SIZE item does not appear.

When the I/O buffer setting is changed, any

downloaded resources (such as fonts or

macros) will need to be downloaded again,

unless they are stored on an optional hard disk

or flash DIMM.

I/O BUFFER SIZE=

100K

10K and up This item appears only when I/O BUFFER=ON.

Specify the amount of memory for I/O buffering.

The maximum amount of memory available for

I/O buffering is determined by the amount of

memory installed in the printer, the languages

installed in the printer, and by other memory

allocations that must be made.

Press [–Value +] to change settings by

increments of 10 (up to 100 KB) or by

increments of 100 (above 100 KB).

Control Panel Menus 3-27

PARALLEL HIGH

SPEED=YES

YES

Select the speed at which data is transmitted to

the printer.

YES: The printer accepts faster parallel

communications used for connections with

newer computers.

NO: The printer accepts slower parallel

communications used for connections with older

computers.

PARALLEL ADV

FUNCTIONS=ON

OFF

Turn the bidirectional parallel communication on

or off. The default is set for a bidirectional

parallel port (IEEE-1284).

This setting allows the printer to send status

readback messages to the computer. (Turning

on the parallel advanced functions might slow

language switching.)

SERIAL

PACING=DTR/DSR

DTR/DSR

XON/XOFF

Select the type of pacing used. Pacing, or

“handshaking” allows the printer to tell the

computer when to send information. The printer

uses XON/XOFF and DTR/DSR signal protocols

rather than ETX/ACK protocol.

DTR/DSR: Select this value if your computer

requires hardware flow control (most personal

computers do).

XON/XOFF: Select this value if your computer

requires software flow control (a UNIX

workstation, for example). The SERIAL

ROBUST XON item appears (see below).

Table 3-11. I/O Menu (continued)

Item Values Explanation

3-28 Printer Operation

SERIAL ROBUST

XON=ON

OFF

This item appears only when SERIAL

PACING=XON/XOFF

. Select the method for

generating XONs.

ON: The printer sends an XON when the printer

is online and when sufficient buffer space is

available. If the host does not receive data within

approximately one second, the printer will

transmit additional XONs at one second

intervals until the host receives data.

OFF: The printer sends one XON when it can

accept more data or when it is online. The

printer does not send XONs every second while

the printer is online and ready for more data.

SERIAL BAUD

RATE=9600

300

600

1200

2400

4800

9600

19200

38400

57600

115200

Select the printer’s baud rate (speed at which

information is transferred) for communicating

from the computer to the printer.

SERIAL DTR

POLARITY=HIGH

HIGH

LOW

Determine whether pin #8 is high or low when

the printer is ready.

HIGH: Pin number 8 is held high when the

printer is ready.

LOW: Pin number 8 is held low when the printer

is ready.

Table 3-11. I/O Menu (continued)

Item Values Explanation

Control Panel Menus 3-29

EIO Menu (Networked Printers)

EIO (enhanced input/output) Menus depend on the particular

accessory product installed in an EIO slot of the printer. If the printer

contains an HP JetDirect print server EIO card, you can configure

basic networking parameters using the EIO Menu. These and other

parameters can also be configured through HP JetAdmin.

Table 3-12. EIO Menu

Item Values Explanation

CFG NETWORK=NO NO

YES

NO: The JetDirect Menu is not accessible.

YES: The JetDirect Menu appears.

NOVELL=ON ON

OFF

Select whether the IPX/SPX protocol stack

(in Novell NetWare networks, for example) is

enabled (on) or disabled (off).

DLC/LLC=ON ON

OFF

Select whether the DLC/LLC protocol stack is

enabled (on) or disabled (off).

TCP/IP=ON ON

OFF

Select whether the TCP/IP protocol stack is

enabled (on) or disabled (off).

ETALK=ON ON

OFF

Select whether the Apple EtherTalk protocol

stack is enabled (on) or disabled (off).

CFG NOVELL=NO NO

YES

NO: The IPX/SPX Menu is not accessible.

YES: The IPX/SPX Menu appears. In the

IPX/SPX Menu, you can specify the frame

type parameter used on your network. The

default is AUTO, to automatically set and limit

the frame type to the one detected.

For Ethernet cards, frame type selections

include EN_8023, EN_II, EN_8022,

EN_SNAP

For Token Ring cards, frame type selections

include TR_8022, TR_SNAP

In the IPX/SPX Menu for Token Ring cards,

you can also specify NetWare Source

Routing parameters, which include SRC

RT=AUTO (default), OFF

, SINGLE R, or

ALL RT

3-30 Printer Operation

CFG TCP/IP=NO NO

YES

NO: The TCP/IP Menu is not accessible.

YES: The TCP/IP Menu appears. In the

TCP/IP Menu, you can specify BOOTP=YES

for TCP/IP parameters to be automatically

loaded from a bootp or DHCP server when

the printer is turned on. If you specify

BOOTP=NO, you can manually set selected

TCP/IP parameters from the Control Panel.

You can manually set each byte of the IP

address (IP), Subnet Mask (SM), Syslog

Server (LG), and Default Gateway (GW).

Also, you can manually set the Timeout time

period.

Note

If no IP address is assigned within the first 5

minutes, the HP JetDirect print server card

will assume a default IP address of

192.0.0.192.

CFG ETALK=NO NO

YES

NO: The EtherTalk Menu is not accessible.

YES: The EtherTalk Menu appears. In the

EtherTalk Menu you can set the AppleTalk

phase parameter (ETALK PHASE=1 OR 2)

for your network.

Table 3-12. EIO Menu (continued)

Item Values Explanation

Control Panel Menus 3-31

Resets Menu

Use this menu with caution. You can lose buffered page data or

printer configuration settings when you select these items. Only reset

the printer under the following circumstances:

●You want to restore the printer’s default settings.

●Communication between the printer and computer has been

interrupted.

●You are using both the serial and parallel I/O ports, and one of the

ports is having problems.

The items in the Resets Menu will clear all memory in the printer,

while [Cancel Job] clears only the current job.

Note Job retention features will be deleted if you do not have the hard disk

accessory. (HP LaserJet 4050 series printer only.)

Table 3-13. Resets Menu

Item Explanation

RESET MEMORY This item clears the printer buffer and the active

I/O input buffer, and makes the Control Panel

defaults current.

Resetting memory during a print job can result in

data loss.

RESTORE FACTORY SETTINGS This item performs a simple reset and restores

most of the factory (default) settings. This item

also clears the input buffer for the active I/O.

RESET ACTIVE I/O CHANNEL This item performs a simple reset and clears the

input and output buffers (for the active I/Os only).

RESET ALL I/O CHANNELS This item performs a simple reset and clears the

input and output buffers for all I/Os.

3-32 Printer Operation

Service Mode

Service Mode should be used only by authorized service personnel.

While in Service Mode, you can:

●Verify and set the page count and serial number. These are

displayed on the Configuration Page.

●Set the Cold Reset Default. (This sets the factory default paper

size to either Letter or A4).

●Turn the diagnostic functions on or off (for software developers

only).

●Clear the Event Log.

●Set the interval at which the PERFORM PRINTER MAINTENANCE

message appears on the Control Panel.

To enter Service Mode:

1Hold down [Select] and [Cancel Job] while turning on the printer

until all of the lights on the Control Panel are lit. (If the Control

Panel reads INITIALIZING, the keys were released too soon.)

2Press the right side of the [Menu] key, then press [Select]. The

message SERVICE MODE is displayed. To exit the Service Mode

press [Go].

Service Mode 3-33

Service Menu

Figure 3-2 Service Menu

Setting the Page Count, Maintenance Count,

and Serial Number

The page count and printer serial number are stored in non-volatile

memory. If it is necessary to replace the Formatter PCA, the page

count should be set to the current value to reflect the age of the Print

Engine. The procedure for setting the serial number is similar to

setting the page count.

Note Before replacing the Formatter PCA, print a Configuration Page to

verify the current page count and serial number of the printer, if

possible. Use the information on the Configuration Page to reset the

page count and printer serial number for the new Formatter PCA.

3-34 Printer Operation

Page Count

The page count stored in NVRAM and displayed on the Configuration

Page printout represents the number of pages which the printer has

printed (excluding engine test prints). If it becomes necessary to

repair a printer by installing a new Formatter, the page count must be

reset so that it represents the age of the printer’s engine rather than

the age of the Formatter.

The page count value is changed using a different method than is

used for other Control Panel values. Instead of increasing the entire

value by increments, each digit can be selected and modified

individually. The following Control Panel keys are used to modify the

page count value:

Table 3-14 shows the sequence of keystrokes used to change the

page count from a value of 000000 to a value of 0010480.

[Select] Enters any changes to the current digit and advances the

cursor one digit to the right. If the last digit is currently

selected, pressing the [Select] key wraps the cursor

around to the first digit.

[Value +] Increases the value of the currently selected digit by one.

Pressing [Value +] when 9 is the value of the currently

selected digit will change the value of the digit to 0.

[– Value] Decreases the value of the currently selected digit by one.

Pressing [– Value] when 0 is the value of the currently

selected digit will change the value of the digit to 9.

Table 3-14. Changing the Page Count

Key Press Display Description

SERVICE MODE

[Menu+] SERVICE MENU Enter the SERVICE MENU.

[Item+] PAGES=0000000 * Advance to the first item in the SERVICE

MENU.

[Select] PAGES=0000000 * Advance the cursor one digit to the right.

Service Mode 3-35

Maintenance Page Count

The maintenance page count should be reset only after a

maintenance kit has been installed.

This will reset the maintenance counter so that the message PERFORM

PRINTER MAINTENANCE will display another 200,000 pages later

(default).

●Hold down the [– Item] and [– Value] keys.

●Turn the printer on.

●Wait for RESET MAINTENANCE COUNT to be displayed and then

release both keys.

[Select] PAGES=0000000 * Advance the cursor one digit to the right.

[Value +] PAGES=0010000 * Increase the value of the third digit by one.

[Select] PAGES=0010000 * Enter the change to the third digit and

advance the cursor one digit to the right.

[Select] PAGES=0010000 * Advance the cursor one digit to the right.

[Value +]

(4 presses)

PAGES=0010400 * Increase the value of the fifth digit by four.

[Select] PAGES=0010400 * Enter the change to the fifth digit and

advance the cursor one digit to the right.

[– Value]

(2 presses)

PAGES=0010480 * Decrease the value of the sixth digit by two.

[Select]

(2 presses)

PAGES=0010480 * Enter the change to the sixth digit and

advance the cursor one digit to the right

causing the cursor to wrap around to the first

digit.

[Go] To exit.

Table 3-14. Changing the Page Count (continued)

Key Press Display Description

3-36 Printer Operation

MAINTENANCE COUNT in the Service Mode Menu sets the page count

interval at which the next service is due for the printer. This is set

initially at the factory to 200,000 pages. (For example, the message

displays at 200,000 pages. If the Printer Maintenance Kit is installed

at 200,114 pages, the message displays 200,000 pages later, at

400,114 pages.) Editing this number is similar to editing the PAGES

item above.

Serial Number

If a Formatter is replaced, then the printer serial number must be

reentered. Editing this number is similar to editing the PAGES item

above.

Cold Reset Paper

The default paper size is stored in NVRAM and when the printer is

cold reset, the default paper size is set to the factory setting. Possible

values are COLD RESET PAPER=LETTER and COLD RESET PAPER=A4.

When replacing the Formatter in countries that use A4 rather than

letter size paper, set the cold reset paper size to A4.

Diagnostics

This menu item enables or disables the use of the firmware diagnostic

features. Possible values are DIAGNOSTICS=OFF* and

DIAGNOSTICS=ON. When enabled, the diagnostic features are

accessible when the printer is in the online READY state by pressing

the [Select] key.

Note This feature is for developers only.

Clear Event Log

This item allows the internal Event Log to be cleared.

Testing the Printer 3-37

Testing the Printer

When you print a Configuration Page, the printer checks its internal

controller and I/O interface, and then prints a test page. You can

review the Configuration Page printout to verify proper installation of

such options as paper trays or printer languages. For more

information, see page 7-52.

Engine Test

The engine test print can be used to verify that the Print Engine is

functioning correctly. For more information, see page 7-11.

3-38 Printer Operation

Resetting the Printer

Cold Reset

Cold reset clears all data from the printer memory and sets all the

defaults back to the factory settings.

CAUTION Performing a Cold Reset resets the HP JetDirect configuration. To avoid

making changes to your configuration, remove the HP JetDirect card

before performing a cold reset.

If possible, print a Configuration Page prior to performing a Cold Reset.

This will document current settings for later reference.

To perform a Cold Reset:

1Turn off the printer.

2While pressing [Go], turn the printer on. COLD RESET appears

briefly on the display, then INITIALIZING appears. After a few

seconds, RESTORING FACTORY SETTINGS appears on the display,

followed by OFFLINE. The cold reset is complete.

3Press [Go] to return the printer online. READY appears on the

display.

Clearing NVRAM

This procedure will clean up the NVRAM by removing old areas that

are not being used.

1Turn off the printer.

2While pressing [Cancel Job] turn the printer on. CLEANUP NVRAM

appears briefly on the display, followed by INITIALIZING. After a

few seconds READY appears.

System Configuration 3-39

System Configuration

MS-DOS System Configuration

To communicate properly with the printer, the MS-DOS environment

requires the addition or modification of MODE commands in the

AUTOEXEC.BAT file. Add or modify the MODE command(s),

depending on the interface configuration, as follows:

Parallel DOS Commands

Most IBM and AT compatible computers default to a parallel printer

port. To ensure that information is sent to your parallel printer port,

type the following MS-DOS command at your MS-DOS prompt or

include it in your AUTOEXEC.BAT file:

MODE LPT1: , , P

For MS-DOS version 4.0 and above, enter:

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

printer port that you are using.

Since the MODE command is an external MS-DOS command (a

program named MODE.COM is run when the MODE command is

invoked), the program file must be contained in the root directory, or in

a directory specified in a preceding PATH command in the

AUTOEXEC.BAT file.

After changing the AUTOEXEC.BAT file, reboot the computer to

initiate the changes.

3-40 Printer Operation

Serial MS-DOS Commands

Most IBM compatible computers default to a parallel printer port. To

ensure that information is sent to the serial printer port, type the

following MS-DOS commands at the MS-DOS prompt, or include

them in the AUTOEXEC.BAT file.

MODE COM1: 9600, N, 8, 1, P

MODE LPT1: =COM1

For MS-DOS version 4.0 or above, enter:

MODE COM1: 9600, N, 8, 1, B

MODE LPT1: =COM1

Note These examples assume that you are using serial printer port COM1.

If you are using COM2 or COM3, replace COM1 with the printer port

that you are using.

Since the MODE command is an external MS-DOS command (a

program named MODE.COM is run when the MODE command is

invoked), the program file must be contained either in the root

directory or in a directory specified in a preceding PATH command in

the AUTOEXEC.BAT file.

After changing the AUTOEXEC.BAT file, reboot the computer to

initiate the changes.

Printer I/O Configuration 3-41

Printer I/O Configuration

Parallel Menu

The default setting for the HIGH SPEED PARALLEL I/O is YES. If it is

set to NO, the interface runs at a slower speed that is compatible with

older computers. When the default is set to YES, the parallel interface

runs at a higher rate supported by newer computers.

Advanced Functions

The ADVANCED FUNCTIONS feature of the printer enables bidirectional

communications between the printer and the host. The default setting

is ON. This default setting (ON) must be active in order to use

HP LaserJet Explorer, the Windows® Printing System, and other

software applications and drivers.

Serial Configuration

Use RS-232C serial configuration when the printer is located 11 to 50

feet (3.35 to 15.24 meters) from the computer. If you need to locate

the printer between 51 and 2000 feet (15.54 and 610 meters) from the

computer, use an RS-422A serial configuration.

Serial I/O settings must be configured correctly for proper serial

communication.

Serial Protocol

When printing with a serial configuration, the same protocol must be

set on both the printer and the computer. Protocol on the printer is set

by changing the Control Panel settings. Protocol on the computer is

set by using DOS commands. The default protocol settings are

described below.

BAUD Rate

The BAUD RATE setting tells the printer how fast information is

transferred to and from the computer. The default setting is

BAUD RATE=9600*.

3-42 Printer Operation

Pacing (Handshaking)

Pacing (or “handshaking”) is a type of communication between the

printer and the computer. This is an important setting in the printer

because it allows the printer to tell the computer when to send

information. If the printer is unable to receive information, for

example, when the print buffer is full or when the printer is out of

paper, a signal is sent to the computer to stop sending information.

When the printer is able to resume receiving information, it sends

another signal to the computer to send more data.

Pacing is set through the Control Panel’s I/O Menu. Two types of

handshaking are supported by the printer:

●Select DTR/DSR through the I/O Menu’s PACING item if the

computer requires hardware flow control (most personal

computers do). Through the I/O Menu’s DTR POLARITY item, the

DTR polarity can be set to High or Low. The default is DTR

POLARITY=HI.

●Select XON/XOFF through the I/O Menu’s PACING item if the

computer requires software flow control (for example, if you are

using a UNIX workstation). Note that status readback messages

are not paced when XON/XOFF is selected. Through the I/O

Menu’s ROBUST XON item, Robust Xon can be set to ON (the

default) or OFF

. Note that the ROBUST XON item only appears

under the I/O Menu if XON/XOFF is selected.

Overview 4-1

4Printer Maintenance

Overview

This chapter discusses the following:

●Cleaning the Printer and Accessories

●Preventative Maintenance

4-2 Printer Maintenance

Cleaning the Printer and Accessories

To maintain high print quality and performance, thoroughly clean the

printer and the paper handling accessories:

●Every time you change the Toner Cartridge (run a cleaning page).

●After printing approximately 10,000 pages.

●Whenever print quality problems occur.

Clean the outside surfaces with a lightly water-dampened cloth. Clean

the inside parts as indicated in Table 4-1. 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 may 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.

Figure 4-1 Location of the Transfer Roller – Do Not Touch!

Cleaning the Printer and Accessories 4-3

Table 4-1. Cleaning the Printer

Component Cleaning Method / Notes

Outside Covers Use 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 with your fingers.

Fuser Use a water-dampened, lint-free cloth.

4-4 Printer Maintenance

Using the Printer Cleaning Page

If Toner specks appear on the front or back side of your print jobs,

follow the procedure below.

From the printer’s Control Panel, do the following:

1Press [Menu] until PRINT QUALITY MENU appears.

2Press [Item] until CREATE CLEANING PAGE appears.

3Press [Select] to create the cleaning page.

4Follow the instructions on the cleaning page to complete the

cleaning process.

Note In order for the cleaning page to work properly, print the page on copier

grade paper (not bond or rough paper).

You might need to create a cleaning page more than once. When

Toner has been cleaned from the Fuser Assembly, shiny black spots

will appear on the page’s black strip.

To ensure good print quality with certain types of paper, use the

cleaning page every time the Toner Cartridge is replaced. If the

cleaning page is frequently needed, try a different type of paper.

Cleaning Spilled Toner

Defective Toner Cartridges can develop leaks. Also, after a paper jam

has occurred, there may be some Toner remaining on the rollers and

guides inside the printer. The pages that print immediately after the

jam may pick up this Toner.

Clean spilled Toner with a cloth dampened with cold water. Do not

touch the Transfer Roller with the damp cloth or with your fingers.

Do not use a vacuum cleaner unless it is equipped with a micro-fine

particle filter.

Preventative Maintenance 4-5

Preventative Maintenance

The preventative maintenance cycle for this printer is every 200,000

pages. To order the maintenance kit see page 8-2. The kit contains

the following replacement parts:

●One Fuser

●One Transfer Roller

●One Tray 1 Roller

●Three Feed Rollers

●Three Separation Rollers

Refer to the instructions included in the kit for detailed replacement

procedures.

Reset Maintenance Count

After the PM kit has been installed, reset the maintenance count.

1Turn the printer off.

2While pressing [– Item] and [– Value] turn the printer on.

RESET MAINTENANCE COUNT appears, followed by INITIALIZING.

After a few seconds READY appears.

4-6 Printer Maintenance

Expected Life of Components

The following table shows the expected life of certain components in

the printer. To order parts, see Chapter 8.

Table 4-2. Life of Components for the HP LaserJet 4000 and 4050 Series Printer

No. Part name Part No. Quantity Expected Life

1Tray 1 Pickup Roller RG5-3718-000CN 1 100,000 pages

2Tray Feed Roller RF5-2490-000CN 1 200,000 pages

3Tray Separation Roller RF5-2490-000CN 1 200,000 pages

4Tray 1 Separation Pad RG5-2655-000CN

(Tray 1 Pickup

Assembly)

1 200,000 pages

5Tray 1 Pickup Solenoid RH7-5172-000CN 1 200,000 pages

6Fuser

100-127V

220-240V C4118-69003

C4118-69004 1

1200,000 pages

200,000 pages

7Transfer Charging Roller RG5-4283-000CN 1 200,000 pages

8Cooling Fan RH7-1335-000CN 1 25,000 hours

9Duplexer Exhaust Fan RH7-1361-000CN 1 25,000 hours

Overview 5-1

5Functional Information

Overview

This chapter presents a generalized functional overview of the printer

and the printing processes. This chapter discusses the following

printer systems:

●Power Supply System

●Engine Controller System

●Formatter System

●Image Formation System

●Paper Feed System

●Basic Sequence of Operation

5-2 Functional Information

Power Supply System

AC/DC Power Distribution

AC power is supplied to the low-voltage power supply circuit in the

Engine Controller Board when the power switch (SW1) is turned on.

The low-voltage power supply circuit supplies +24 VDC and +3.3

VDC required for the printer.

+24 VDC is supplied to drive the main motor, scanner motor and fan,

and to the high-voltage power supply. +3.3 VDC is used for sensors

and ICs on the engine controller board. +24 VDC is divided into +24

VA which is normally supplied from the low-voltage power circuit, and

+24VB which is interrupted when the door switch (SW101) turns off

by opening the upper cover.

Figure 5-1 Low-voltage Power Supply Circuit

If a short-circuit or other problems on the load side cause an

excessive current flow from the +24VDC, or +3.3 VDC power supplies

or generate abnormal voltage, the excess-current protection system

and excess-voltage protection system automatically shut off the

output voltage to protect the power supplies.

If the protection systems are activated and the power supply circuit

does not output DC voltage, it is necessary to turn the printer off,

correct the problem in the faulty load, then turn the printer on again.

The circuit has two fuses which break the circuit and cut off the output

voltage if excess current flows through the AC line.

Power Supply System 5-3

Overcurrent Overvoltage Protection

The Fusing Heater Safety Circuit is located on the Engine Controller

Board, and constantly monitors the fusing temperature.

In case of abnormality, the output from this circuit turns off the relay

(RL101) and interrupts the power to the fusing heater.

If an increase in the temperature of the Fusing Heater causes the

Thermistor Output voltage to exceed about 1.2V (240° C), the output

of pin #13 of the comparator (IC301) becomes “L”.

When the output of pin #14 becomes “L” and Q302 is turned off, the

relay (RL101) is turned off.

To protect the Fuser from excessive voltages, the printer has the

following three protective functions:

●The CPU monitors the voltage of TH901. If it is abnormal, the

CPU assesses fusing heater failure and turns off the relay

(RL101). At the same time, it reports the fusing heater failure to

the Formatter.

●If the temperature of the fusing heater rises abnormally and the

voltage of TH901 falls below about 1.2V (240° C), the fusing

heater’s safety circuit interrupts the power to the fusing heater,

regardless of CPU outputs.

●If the temperature of the fusing heater rises abnormally and the

temperature of the Thermal Fuse exceeds about 230° C, the

temperature fuse melts, which interrupts the power to the fusing

heater.

5-4 Functional Information

High-voltage Power Distribution

Figure 5-2 Engine Controller Board

In response to the instructions from the microprocessor (CPU:IC 501)

on the Engine Controller Board, this circuit applies the superimposed

voltage of DC voltage and AC voltage to the primary charging roller

and Developing Cylinder, and a positive or negative DC voltage to the

transfer charging roller.

According to the image density information sent from the Formatter,

this circuit varies the primary DC bias and developing DC bias to

adjust the image density.

Power Supply System 5-5

Toner Cartridge Detection

The Toner Cartridge has a Toner sensor. The circuit compares the

output value of the developing AC bias and the output value from the

antenna inside the Cartridge, and outputs the Toner detection signal.

The CPU detects the remaining Toner level and the presence of the

Cartridge when the developing bias is applied to the Developing

Cylinder. The remaining Toner level is always detected when the

developing bias is applied. The presence of the Cartridge is detected

only when the developing bias is applied during the initial rotation.

5-6 Functional Information

Engine Controller System

The following systems and functions are controlled by the engine

controller board:

●DC power distribution (+3.3V DC, +5V DC, +24VA)

●Laser and scanner drive

●Paper motion monitoring and control (photosensors and flags)

●Clutches (tray pickup and Tray 1 feed)

●Engine Test

●Motors (main drive, scanner, and fans)

The operation sequences of this printer are controlled by the CPU of

this circuit. When the power switch of the printer is turned on and the

printer enters the standby mode, the CPU outputs the signals to drive

the loads such as Laser Diode, motors, and solenoids, based on the

print commands and the image data input from the external device.

Engine Controller System 5-7

Figure 5-3 Engine Controller Board

5-8 Functional Information

Engine Controller Board Inputs and Outputs

Figure 5-4 Engine Controller Board I/O (1 of 4)

Engine Controller System 5-9

Figure 5-5 Engine Controller Board I/O (2 of 4)

5-10 Functional Information

Figure 5-6 Engine Controller Board I/O (3 of 4)

Engine Controller System 5-11

Figure 5-7 Engine Controller Board I/O (4 of 4)

5-12 Functional Information

Laser and Scanner Drive

Based on information received from the Formatter, the Engine

Controller Board sends signals to the Laser Scanner Assembly to

modulate the Laser Diode on and off and to drive the Laser Scanner

motor. See “Image Formation System” on page 5-22 for more

information.

Paper Motion Monitoring and Control

The Engine Controller Board controls paper motion by continuously

monitoring the various Paper Sensors and coordinating paper

movement with the other print processes. For more information, see

“Paper Feed System” on page 5-33.

Solenoids, Sensors, Clutches, and Switches

See “Engine Controller Board Inputs and Outputs” on page 5-8.

Engine Test Print

See “Engine Test” on page 7-11.

Engine Controller System 5-13

Motors

See “Timing Diagram” on page 5-50 for specific timing details for the

printer motors.

The Main Motor, MT1, is controlled by the Engine Controller Board.

The Main Motor drives the Main Gear Assembly and rotates during

the initial rotation period (following power-on), the print period, the last

rotation period, or whenever the printer’s Top Cover is opened and

closed.

Figure 5-8 Main Motor Control

The Main Motor is a DC brushless motor and is unified with the motor

drive circuit.

The CPU (IC501) sets the Main Motor Drive signal (/MON) to “L” and

rotates the Main Motor. When the HP LaserJet 4000 series printer is

printing at 1200 dpi, the CPU sets the main motor rotation switching

signal (/HALF) to “L” and decreases the rotation speed of the Main

Motor to half. The HP LaserJet 4050 prints 1200 dpi at engine speed.

5-14 Functional Information

The Scanner Motor is controlled and monitored by the Engine

Controller Board. It rotates the Scanner Mirror during the initial

rotation period and the print period.

The Fan Motor is controlled and monitored by the Engine Controller

Board. The fan operates at full speed during the printing modes. The

Fan turns off in PowerSave mode after the Fuser cools down.

Formatter System 5-15

Formatter System

The Formatter PCA is responsible for the following:

●Controlling the PowerSave mode

●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

The Formatter PCA receives a print job from the Bidirectional

Interface and separates it into image information and instructions

which control the printing process. The Engine Controller Board

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 PCA also provides the electrical interface and

mounting locations for two EIO cards, additional memory DIMMs, and

the Hard Disk accessory, and the HP Fast InfraRed Receiver

(HP LaserJet 4050 series printer only).

PowerSave

This feature (accessed from the Configuration Menu) conserves

power by shutting down the Fuser and Exhaust Fans after the printer

has been idle for an adjustable period of time. The printer retains all

printer settings, downloaded fonts, and macros while in PowerSave

mode. The default setting is POWERSAVE ON, with a 30 minute idle

time. (PowerSave can also be turned OFF from the Control Panel.)

The printer exits PowerSave mode and enters the warm-up cycle

when any of the following occurs:

●A print job, valid data, or a PML or PJL command is received at

the parallel port, serial port, FIR port, and EIO card

●A Control Panel key is pressed

●The Top Cover is opened and then closed

●A paper tray is opened and then closed

●The Engine Test button is pressed

5-16 Functional Information

Note Printer error messages override the PowerSave message. The printer

will enter PowerSave mode at the appropriate time, but the error

message will continue to be displayed.

Resolution Enhancement technology (REt)

The Formatter PCA contains circuitry for Resolution Enhancement

technology (REt), which modifies the standard video dot data on its

way to the Engine Controller Board to produce “smoothed”

black-to-white boundaries. REt can be turned on or off from the

Control Panel, or from some software applications. The default setting

is medium.

Note REt settings sent from software applications or printer drivers override

the Control Panel settings.

EconoMode

The EconoMode setting uses up to 50% less Toner than standard

mode printing by reducing the dot density. However, EconoMode

does not extend Toner Cartridge component life. EconoMode, which

can be thought of as “draft mode” can be selected from the Control

Panel (Print Quality Menu) and through some software applications

and printer drivers. The default setting is off.

Note EconoMode does not affect print speed, memory usage, nor extend

the Toner Cartridge’s life.

Formatter System 5-17

Input/Output

Parallel Interface

The Formatter PCA receives incoming data through its Bidirectional

Interface (IEEE 1284). The I/O provides high speed and two way

communication between the printer and the host, allowing the user to

change printer settings and monitor printer status from the host

computer. The user may configure the HIGH SPEED item in the Control

Panel Menu. The default setting, YES, allows the I/O to run at the

higher speeds supported by most newer computers. When set to NO,

the parallel interface runs at the slower mode that is compatible for

older computers. The user may also configure the ADVANCED

FUNCTIONS item. The default setting, ON, allows for two way parallel

communications. The OFF mode disables the advanced functionality.

The I/O is compatible with the Bidirectional Parallel Interface

standard.

Expanded I/O

The optional Expanded I/O card can be installed in the slots provided

on the Formatter PCA. It provides automatic I/O switching between

multiple computers or networks connected to the printer. The network

versions for the HP LaserJet 4000 series printers include LocalTalk

and the HP JetDirect Multi-protocol Network Card with

Ethernet/10Base-T and 10Base-2. The network versions for the

HP LaserJet 4050 series printers include the HP JetDirect Print Server

with 10/100 Base TX.

HP Fast InfraRed Receiver

The HP Fast InfraRed Receiver enables wireless printing from any

iRDA-compliant portable device (such as a laptop computer) to the

HP LaserJet 4050, 4050 N, 4050 T, or 4050 TN printer.

The printing connection is maintained by positioning the sending

infrared 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 infrared port.

Flash

Flash is provided in optional 2 MB and 4 MB flash memory DIMMs for

storing forms, fonts, and signatures.

5-18 Functional Information

Disk

The disk accessory is mounted on the rear of the Formatter PCA. The

optional greater than 1 GB EIO-based hard drive is used for creating

multiple original prints (mopies) and storing forms, fonts, and

signatures.

Local Talk I/O

The printer implements AppleTalk networking protocol through

LocalTalk hardware. The LocalTalk network cable (HP P/N 92215N) is

connected through the EIO card. The LocalTalk hardware is an

optional feature for the HP LaserJet 4000, 4000 T, and 4050 series

printers. The LocalTalk hardware is bundled with the HP LaserJet

4000 N/TN printers.

CPU

The HP LaserJet 4000 series printer’s Formatter PCA incorporates a

100MHz RISC processor. The HP LaserJet 4050 series printer’s

Formatter PCA incorporates a 133MHz RISC processor.

Printer Memory

Note If the printer encounters difficulty managing available memory, a

clearable warning message will be displayed on the Control Panel.

Some printer messages are affected by the Auto Continue and

Clearable Warning settings from the Configuration Menu in the printer’s

Control Panel. If CLEARABLE WARNING=JOB is set on the Control Panel,

warning messages display on the Control Panel until the end of the job

from which they were generated. If CLEARABLE WARNING=ON is set,

warning messages display on the Control Panel 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 displays until [Go] is pressed.

Read Only Memory (ROM)

Besides storing microprocessor control programs, the ROM stores

dot patterns of internal character sets (fonts).

Formatter System 5-19

Random Access Memory (RAM)

The RAM contains the page and I/O buffers and the font storage area.

It stores printing and font information received from the host system,

and can also serve to temporarily store a full page of print image data

before the data is sent to the print engine (see “Page Protect” below).

RAM memory capacities for each printer are shown in “Printer

Features” on page 1-2. Memory capacity can be increased by adding

DIMMs to the Formatter PCA. Note that adding memory (DIMMs)

may also increase the print speed of complex graphics.

DIMM Slots

The DIMM slots may be used to add memory, fonts, or firmware

upgrades. Note that DIMMs and SIMMS are not compatible.

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 turned off or disconnected.

Memory Enhancement technology (MEt)

The Hewlett-Packard Memory Enhancement technology (MEt)

effectively doubles the standard memory through a variety of font and

data compression methods.

Note MEt is only available in PCL mode; it is not functional when printing in

PS mode.

5-20 Functional Information

Page Protect

Page complexity (rules, complex graphics, or dense text) may exceed

the printer’s ability to create the page image fast enough to keep pace

with the image formation process. If Page Protect is disabled, and a

page is too complex, it may print in parts (for example, the top half on

one page and the bottom half on the next page). Some print data loss

is likely in these instances, and the printer will display the 21 PAGE

TOO COMPLEX error message, alternating with PRESS GO TO

CONTINUE.

Page Protect allows the Formatter to create the entire page image in

page buffer memory before physically moving the paper through the

printer. This process ensures that the entire page will be printed.

Page Protect applies only to PCL printing. The default setting is Auto.

PJL Overview

Printer Job Language (PJL) is an integral part of configuration, in

addition to the standard Printer Command Language (PCL). With

standard cabling, PJL allows the printer to perform functions such as:

●Two-way communication with the host computer through a

Bidirectional Parallel Connection. The printer can tell the host

such things as the Control Panel settings, and it allows the

Control Panel settings to be changed from the host.

●Dynamic I/O switching allows the printer to be configured with a

host on each I/O. The printer can receive data from more than

one I/O simultaneously, until the I/O buffer is full. This can occur

even when the printer is offline.

●Context-sensitive switching allows the printer to automatically

recognize the personalities (PS or PCL) of each job and configure

itself to serve that personality.

●Isolation of print environment settings from one print job to the

next. For example, if a print job is sent to the printer in landscape

mode, the subsequent print jobs print in landscape only if they are

formatted for landscape printing.

Formatter System 5-21

PML

PML is a Printer Management Language that allows remote

configuration and status readback through the I/O ports.

Control Panel

The Formatter PCA sends and receives printer status and command

data via a Control Panel PCA. See “Using the Control Panel” on page

3-2, and “Printer Messages” on page 7-17 for more information.

5-22 Functional Information

Image Formation System

The image formation system is the main system in the printer. It

consists of six stages:

When the Formatter Board sends the print signal to the Engine

Controller Board, it drives the Main Motor to rotate the Photosensitive

Drum, the Developing Cylinder, the Primary Charging Roller, and the

Transfer Charging Roller.

The Primary Charging Roller places a uniform negative charge on the

surface of the Photosensitive Drum. The laser beam modulated by

the video signal is illuminated on the Photosensitive Drum surface to

form the latent image on the Drum with the Laser Diode.

The latent image formed on the Photosensitive Drum is changed to a

visual image by the Toner on the Developing Cylinder, then

transferred to the paper by the Transfer Charging Roller. The residual

Toner on the Photosensitive Drum surface is scraped down with the

cleaning blade. The potential on the Drum is uniformed by the

Primary Charging Roller to prepare for a new latent image.

The Cartridge has a Toner sensor that detects the remaining Toner

level and the presence of the Cartridge.

If the Toner in the Cartridge becomes lower than the specified level or

if there is no Cartridge in the printer, it is reported to the Formatter.

1. Cleaning 4. Developing

2. Conditioning 5. Transferring

3. Writing 6. Fusing

Image Formation System 5-23

Figure 5-9 Image Formation System

After the image has been transferred to the paper, it is then fused

onto the paper by heat and pressure at the Fuser.

5-24 Functional Information

Toner Cartridge

Figure 5-10 Toner Cartridge

A major portion of the Image Formation System is contained in the

Cartridge as shown in the figure above.

The Toner Cartridge is the “heart” of the Image Formation System. It

houses the cleaning, conditioning, and developing steps of the

process. The Toner Cartridge contains the photosensitive Drum,

primary charging roller, developing station, Toner cavity, and cleaning

station. Including these components that wear, degrade, or are

consumed in the replaceable Toner Cartridge eliminates the need for

a service call when replacement is required.

The printer also has a new Cartridge drive system that minimizes

banding, with more constant paper speed.

Image Formation System 5-25

Photosensitive Drum

The special properties of the Photosensitive Drum allow an image to

be formed on the Drum surface and then transferred to paper. The

Drum is an aluminum cylinder. The outside of the cylinder is coated

with a layer of organic-photoconductive material (OPC) which is

non-toxic. The OPC material has properties similar to a

photo-resistor. It becomes electrically conductive when exposed to

light. (The negative charges deposited on the Drum are conducted to

the ground potential of the Drum base.) Areas not exposed to light

remain non-conductive and maintain their negative charge. The

aluminum base of the photosensitive Drum is electrically connected

to ground potential.

Figure 5-11 Photosensitive Drum

5-26 Functional Information

Cleaning the Drum

The cleaning blade is in contact with the surface of the Drum at all

times. As the Drum rotates during printing, excess Toner is stored in

the waste Toner receptacle.

Figure 5-12 Cleaning the Drum

Image Formation System 5-27

Conditioning the Drum

After the Drum is cleaned, it must be conditioned. This process

consists of applying a uniform negative charge on the surface of the

Drum with the Primary Charging Roller. The Primary Charging Roller

is coated with conductive rubber with an AC bias applied to erase any

residual charges and maintain a constant Drum surface to create a

uniform negative potential on the Drum surface. The amount of DC

voltage is modified by the print density setting.

Figure 5-13 Primary Charging Roller

5-28 Functional Information

Writing the Image

During the writing process, a modulated Laser Diode projects the

beam onto the rotating six-sided Scanning Mirror. As the mirror

rotates, the beam reflects off the mirror, through a set of focusing

lenses, through a slot in the rear of the Toner Cartridge, and onto the

Photosensitive Drum. The beam sweeps the Drum from left to right,

discharging the negative potential wherever the beam strikes the

surface. This creates a latent electrostatic image, which later is

developed into a visible image.

Figure 5-14 Writing the Image

Because the beam is sweeping the entire length of the Drum and the

Drum is rotating, the entire surface area of the Drum can be covered.

The speed of the Scanner Motor (which turns the Scanning Mirror)

and the speed of the Main Motor (which turns the Drum) are

synchronized, and each successive sweep of the beam is offset by

1/1200th of an inch. The beam can be turned on and off to place a dot

of light every 1/1200th of an inch. This is how the printer achieves its

1200x1200 dpi resolution. After the writing process, the Drum surface

has an invisible (latent) electrostatic image.

At the end of each sweep, the beam strikes the Beam Detect Lens,

generating the Beam Detect Signal (BD). The BD signal is sent to the

Engine Controller Board, where it is converted to an electrical signal

used to synchronize the output of data (/VDO) for one sweep (scan

line) and to diagnose problems with the Laser Diode or Scanner

Motor.

Image Formation System 5-29

Developing the Image

The developing process develops the latent electrostatic image into a

visible image on the Drum. The Developing Unit consists of a metallic

cylinder that rotates around a fixed magnetic core inside the Toner

cavity. Toner is a powdery substance made of black plastic resin

bound to iron particles, which is uniformly attracted to the magnetic

core of the cylinder.

The Toner particles obtain a negative surface charge by rubbing

against the Developing Cylinder which is connected to a negative DC

supply. The negatively charged Toner is attached to the discharged

(exposed, grounded) areas. An AC potential is applied to the

Developing Cylinder to decrease the attraction between the Toner

and the magnetic core of the cylinder, and to increase the repelling

action of the Toner against the areas of the Drum not exposed to laser

light. This AC potential improves density and contrast.

Figure 5-15 Developing the Image

The Print Density Control in the Control Panel Menu adjusts the DC

bias of the Developing Cylinder by changing the force of attraction

between the Toner and Drum. A change in the DC bias causes either

more or less Toner to be attracted to the Drum, which in turn either

increases or decreases the print density. Both the primary and

Developer DC bias voltages are changed in response to the density

setting.

5-30 Functional Information

Transferring the Image

During the transferring process the Toner image on the Drum surface

is transferred to the paper. A positive charge applied to the back of

the paper by the transfer roller causes the negatively charged Toner

on the Drum surface to be attracted to the page.

The small diameter of the Drum, combined with the stiffness of the

paper, causes the paper to peel away from the Drum. The static

eliminator teeth also help separate the paper from the Drum. The

static eliminator teeth weaken the attractive forces between the

negatively charged Drum surface. After separation, the Drum is

cleaned and conditioned for the next image.

Figure 5-16 Transferring the Image

Image Formation System 5-31

Image Fusing/Variable Fusing Temperature

During the fusing process, the Toner is fused into the paper by heat

and pressure to produce a permanent image. The paper passes

between a heated Fusing Roller and a soft Pressure Roller. This

melts the Toner and presses it into the paper.

The Fusing Roller contains a ceramic heating element that provides

heat for the fusing process. Fusing temperature is monitored by the

Engine Controller Board, via the Thermistor TH901. The Engine

Controller Board maintains a temperature of about 383° F (195° C)

during print mode. If the Fusing System overheats (about

428° F/220° C), a relay opens, interrupting power to the Fusing

Heater, causing a Fuser error message (50.X FUSER ERROR). If the

Fusing System exceeds 464° F (240° C), the thermal fuse will open,

cutting off power to the Fuser.

Figure 5-17 Image Fusing

5-32 Functional Information

Variable Fusing Temperature

Figure 5-18 Fusing Temperature Control

Variable fusing temperature is a feature that gives the user or service

technician the ability to adjust the fusing temperature based on the

media being used in the printer. The default mode is normal and

should be optimal for most users. There is an optional low and high

Fuser mode selection. If very heavy or rough media is being used,

then high Fuser mode is beneficial. If transparencies or light media

are being used, then low Fuser mode might be appropriate.

CONFIGURE FUSER MODE is in the Paper Handling Menu and when set

to the default of NO, paper types are not displayed in the menu. When

CONFIGURE FUSER MODE is set to YES, the different paper types are

then displayed in the menu.

Note Fusing modes only operate for A4-, letter-, and legal-sized paper.

Paper Feed System 5-33

Paper Feed System

Figure 5-19 Paper Feed Subsystem

5-34 Functional Information

Figure 5-20 Paper Path

The presence of paper in Tray 1 is detected by the Tray 1 Paper

Sensor (PS105). Presence of paper in Tray 2 is detected by the Tray 2

Paper Sensor (PS101) for the HP LaserJet 4000, 4000 N, 4050 and

4050 N; and by the Upper Tray Paper Sensor (PS101) or the Lower

Tray Paper Sensor (PS102) for the HP LaserJet 4000 T, 4000 TN,

4050 T, and 4050 TN.

Both the size of the paper in the tray and the presence of a tray are

detected by the three switches (SW600, 601, 602) on the Paper Size

Detection PCA for the HP LaserJet 4000, 4000 N, 4050, and 4050 N,

Paper Feed System 5-35

and by the six switches (SW600, 601, 602, 603, 604, 605) on the

Paper Size Detection PCA for the HP LaserJet 4000 T, 4000 TN,

4050 T, and 4050 TN.

While the Main Motor rotates, the Tray 1 Pickup Solenoid (SL102) is

turned on, the Tray 1 Pickup Roller rotates, and a sheet of paper is fed

into the printer.

The paper passes the pre-feed roller, which compensates for the

skew of the paper.

After the top of page sensor (PS103) detects the leading edge of the

paper, the horizontal synchronization signal (/TOP) is sent from the

Engine Controller Board to the Formatter.

After the Formatter receives the /TOP signal, the /VDO signal is sent;

this synchronizes the leading edge of the image on the Drum with the

leading edge of the paper. The paper goes through transfer,

separation, and fusing stages, passes through the delivery unit, and

is delivered to the Top Output Bin or Rear Output Bin.

There are four photo-interrupters (PS102, PS103, PS106, PS501) in

the paper path that detect the presence of paper. If the paper does

not reach or pass these sensors within a prescribed time interval, the

microprocessor on the Engine Controller Board notifies the Formatter

of a paper jam.

Clutches and Sensors

See “Reference Diagrams” starting on page 7-84 for locations of

switches, sensors, and clutches.

5-36 Functional Information

Printing from Tray 1

The presence of paper in Tray 1 is detected by the Tray 1 Paper

Sensor (PS105).

When the Engine Controller Board receives the /PRNT signal from

the Formatter, the printer starts the initial rotation phase. (This

consists of Main Motor warm-up, Scanner Motor warm-up,

high-voltage control sequence and Fuser warm-up.) When the initial

rotation phase ends, the Tray 1 Pickup Solenoid (SL102) is turned on.

The cam rotates, the paper tray lifter rises, and the paper comes in

contact with the Tray 1 Pickup Roller. At the same time, the Tray 1

Pickup Roller rotates once and a sheet of paper in Tray 1 is picked up.

The Separation Pad removes the unnecessary sheets, and the paper

is at the Top-of-Page Sensor (PS103) when SL102 is turned back on

again.

The paper then reaches the Registration Arm, where its skew is

corrected. Then it goes through transfer, separation, and fusing

stages, passes through the delivery unit, and is delivered to the tray.

Figure 5-21 Tray 1 Pickup Timing

Paper Feed System 5-37

Figure 5-22 Tray 1 Pickup

5-38 Functional Information

Printing from Tray 2

When the Formatter inputs the /PRNT signal to the printer, the Main

Motor (M1) starts rotation. When the Main Motor reaches its

prescribed speed, the Feed Roller Clutch (CL101) and Tray 2 Pickup

Solenoid (SL 101 or SL 103) are turned on. (The Tray 2 Pickup Roller,

Tray 2 Feed Roller, Separation Roller, and Feed Rollers are driven by

the Main Motor rotation.)

The Tray 2 Pickup Roller, driven by the Pickup Solenoid, rotates once

and picks up the paper in the tray. The unnecessary sheets are

removed by the Separation Roller and the paper is fed to the pre-feed

sensor (PS102).

The CPU monitors the condition of the PS102 for a prescribed period

of time. If PS102 does not detect paper within that time, the CPU

resumes feeding the paper, maintaining the appropriate

between-page distance for continuous printing.

The paper then reaches the Registration Arm, where its skew is

corrected. Then it goes through transfer, separation, and fusing

stages, passes through the delivery unit, and is delivered to the tray.

Figure 5-23 Tray 2 Pickup Timing

Paper Feed System 5-39

Figure 5-24 Tray 2 Pickup

5-40 Functional Information

Multi-Feed Prevention Mechanism

When feeding paper from Tray 2, the printer uses the Separation

Roller to prevent multi-feeding. Normally, the Separation Roller is

imparted with a rotational force in the same direction as the Feed

Roller. However, since the Separation Roller is equipped with a

Torque Limiter, it rotates with Feed Roller 1 by transmission of its

rotational force via the transported paper. On the other hand, if

multiple sheets of paper are picked up, the low friction force between

the sheets of paper results in a weak rotational force being

transmitted to the Separation Roller from Feed Roller 1.

Consequently, the Separation Roller’s own rotational force separates

the extra sheet.

Figure 5-25 Multi-Feed Prevention Mechanism

Paper Feed System 5-41

Printing from the Optional 500-sheet

Universal Tray

The operation sequences of the Paper Feeder are controlled by the

Paper Feeder Driver. A 4-bit microprocessor is used in the Paper

Feeder Driver, which controls the sequences of the Paper Feeder and

the serial communication with the Engine Controller Board.

The Engine Controller Board outputs the pickup command to the

Paper Feeder Driver with the necessary timing.

The Paper Feeder Driver drives the solenoid in response to the

pickup command. The Paper Feeder Driver also returns the status of

the Paper Feeder to the Engine Controller Board.

+24VDC is supplied to the Paper Feeder from the printer, and +3.3V

for the integrated circuits is generated from +24VDC inside the Paper

Feeder Driver.

Figure 5-26 Paper Feeder Driver I/O

5-42 Functional Information

Pickup and Feeding

The Paper Feeder picks up the paper from the installed trays and

feeds the paper to the printer. The flow of the paper is shown below.

Figure 5-27 Paper Feed from Trays

The paper size and the presence of the 500-sheet Tray are detected

by three switches (SW801, 802, 803) on the Paper Feeder Driver

PCA. The relationship between the switch combinations and the

paper sizes is the same as for the printer.

The Paper Feeder is driven by the Main Motor (M101) of the printer.

When the /PRNT signal is sent to the Paper Feeder from the

Formatter, the Main Motor (M101) of the printer starts rotation. When

the Main Motor reaches its prescribed speed, the Paper Feeder

Driver PCA receives the pickup command from the Engine Controller

Board, and the Paper Feeder Pickup Solenoid (SL801) is turned on.

(The Pickup Roller, Feed Roller, and Separation Roller are driven by

the Main Motor’s rotation.)

The Pickup Roller, driven by the Solenoid, rotates once, picking up

the paper inside the 500-sheet tray. Any unnecessary sheets are

removed by the Separation Roller and the paper is fed to the pre-feed

sensor (PS102) of the printer.

Paper Feed System 5-43

The CPU on the Engine Controller Board monitors the conditions of

the PS102 for a prescribed period of time after the pickup starts. If the

PS102 does not detect paper within that time interval, the CPU turns

off the Feed Roller clutch (CL101) to stop the paper after the top of

page sensor (PS103) detects the presence of the preceding page.

The paper then reaches the Registration Arm, where its skew is

corrected. Then it goes through transfer, separation, and fusing

stages, passes through the delivery unit, and is delivered to the

output bin.

Figure 5-28 Paper Feed Pickup

5-44 Functional Information

Envelope Feeder

The operation sequences of the Envelope Feeder are controlled by

the Envelope Feeder Driver. A 4-bit microprocessor is used in the

Envelope Feeder Driver, which controls the sequences of the

Envelope Feeder and the serial communication with the Engine

Controller Board of the printer.

The Engine Controller Board outputs the pickup command to the

Paper Feeder Driver with the necessary timing.

The Envelope Feeder Driver drives the solenoid in response to the

command. The Envelope Feeder Driver also returns the Envelope

Feeder status to the Engine Controller Board.

+24VDC is supplied to the Envelope Feeder from the printer, and

+3.3V for the ICs is generated from the +24VDC inside the Paper

Feeder Driver.

Pickup and Feeding

The Envelope Feeder picks up the envelope from the Envelope

Feeder and feeds it to the printer. The envelope path is shown below.

Figure 5-29 Envelope Feed

The Envelope Feeder is driven by the Main Motor (M101) of the

printer.

When the /PRNT signal is sent to the printer from the Formatter, the

printer starts the initial rotation phase. (This phase consists of Main

Motor start-up, Scanner Motor start-up, High-voltage Control

Sequence, and Fusing unit start-up.) When the initial rotation phase

Paper Feed System 5-45

is completed, the Envelope Feeder Driver PCA receives the pickup

command from the Engine Controller Board and turns on the

envelope pickup solenoid (SL901).

The Pickup Roller, Feed Roller and Separation Roller are rotated

sequentially by the Main Motor rotation, and an envelope is picked up.

Then, any unnecessary envelopes are removed by the Separation

Roller, and the envelope is fed to the printer.

Figure 5-30 Envelope Feed Pickup

5-46 Functional Information

Duplexer

The operation sequences of the Duplexer are controlled by the

Duplexer Driver. A 4-bit microprocessor is used in the Duplexer

Driver, which controls the sequences of the Duplexer and the serial

communication with the Engine Controller Board.

The Duplexer Driver drives the Solenoid, Motors, and Fan according

to commands sent from the Engine Controller Board to the Duplexer

and Duplex Pickup command via serial communication. The Duplexer

also returns its status to the Engine Controller Board.

+24VDC is supplied to the Duplexer from the printer, and +5V for the

ICs is generated from the +24VDC inside the Duplexer Driver.

Reversing and Duplexer Pickup

The paper is fed to the Duplexer by the Top Output Bin Deflector. This

Top Output Bin Deflector moves in conjunction with the Top Output

Bin. However, the Top Output Bin Deflector is controlled by the

Duplexer Solenoid (SL701) when the Top Output Bin is closed.

The feed direction of the paper in the Duplexer is controlled by the

Reversing Roller. The paper is then transported by the Oblique Roller

and Feed Roller so that its edge contacts with the left panel to correct

its skew.

The Duplexer has two stepping motors, the Reversing Motor (M701)

and the Duplex Feed Motor (M702). Normal and reverse rotations are

controlled by the Duplexer Driver.

Paper Feed System 5-47

Figure 5-31 Paper Path for the Duplexer

5-48 Functional Information

Figure 5-32 Paper Feed for the Duplexer

Paper Jam

There are four photointerrupters (PS102, PS103, PS106, PS501) in

the paper path for detecting the presence of the paper.

If the paper does not reach or pass three sensors within the

prescribed time, the microprocessor in the Engine Controller Board

notifies the Formatter of a paper jam.

Basic Sequence of Operation 5-49

Basic Sequence of Operation

The Formatter PCA and the Engine Controller Board share

information during printer operation. The Interface PCA forms a link

which operates as a serial data bus. This allows printer status,

command, and dot-image data to be passed between the two PCAs.

Table 5-1 shows the general timing of the printer events. The following

events take place during normal printer operation:

Table 5-1. Printer Timing

Period Timing Purpose

WAIT From power on to the end of Main

Motor initial rotation. Clears the Drum surface potential

and cleans the Transfer Roller.

STBY (standby) From the end of the WAIT or the

LSTR period until the input of the

PRNT signal from the Formatter.

Or from the end of the LSTR period

until power off.

Maintains the printer in ready state.

INTR (initial rotation) From the input of the PRNT signal

from the Formatter until the Engine

Controller outputs the TOP signal.

Stabilizes the photosensitive Drum

sensitivity in preparation for

printing. Also cleans the Transfer

Roller.

PRNT After the end of initial rotation until

the top of the page sensor detects

the trailing edge of the paper.

Forms images on the

photosensitive Drum based on the

/VDO signal from the Formatter

and transfers the image to paper.

LSTR (last rotation) From the primary voltage (DC) off

until the main motor stops.

If another PRNT signal is sent from

the Formatter, the printer returns to

the INTR period. If not, it returns to

the STBY period.

Delivers the last sheet of paper and

cleans the Transfer Roller.

5-50 Functional Information

Figure 5-33 Timing Diagram

Overview 6-1

6Removing and

Replacing Parts

Overview

This chapter discusses the following:

●Removal and Replacement Strategy

●Removing Covers

●Removing Assemblies

●Separating the Engine Module from the Paper Feed Module

6-2 Removing and Replacing Parts

Removal and Replacement Strategy

This chapter describes the complete disassembly of the printer. In

every instance, tasks that must be performed before beginning the

procedure are listed first. Remove the assemblies in the order listed

to prevent damage during re-assembly.

To ensure optimum print quality, the printer will prompt to have routine

maintenance performed every 200,000 pages. When the message

PERFORM PRINTER MAINTENANCE appears on the Control Panel, the

Printer Maintenance Kit must be installed. See page 4-5.

Servicing the printer involves replacing printed circuit and

electro-mechanical assemblies. Do not repair component failures

within these assemblies. In all instances, replace the failed assembly.

The replacement procedure is the reverse of the removal procedure,

except where specific instructions are provided.

WARNING! Some sheet metal edges, particularly around the formatter cage, are

sharp. Be careful when working in these areas to avoid cutting yourself.

CAUTION The printer contains parts that are sensitive to

Electrostatic-Static Discharge (ESD). Always observe

proper ESD procedures when servicing the printer. The

ESD symbol appears in this chapter when the parts

being serviced are especially susceptible to ESD

damage.

It is usually best to remove and replace the covers in the order shown.

Turn the printer off and unplug the power cord and any cables.

Removal and Replacement Strategy 6-3

Tools

●Phillips #2 magnetized screwdriver with 6-inch shaft

●Flat-blade screwdriver with 6-inch shaft

●Needle-nose pliers

●Penlight

Screws Used in the Printer

All screws used in the printer are Phillips head, which require a

Phillips screwdriver. The following figure shows the difference

between a Phillips and a Posidriv screwdriver. Note that the Phillips

tip has more beveled surfaces.

CAUTION Using a Posidriv screwdriver will damage the screw heads. Use Phillips

only.

Figure 6-1 Comparing Phillips and Posidriv Screwdrivers

Table 6-1 on page 6-4 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.

Phillips Posidriv

6-4 Removing and Replacing Parts

Table 6-1. Screws Used in the Printer

Drawing and Description Purpose

Threaded Phillips with captive star washer

Used to fasten metal to metal

when good electrical contact is

needed.

Silver Self-tapping Phillips screw

Used to fasten metal or plastic to

plastic mainframes.

Black Self-tapping Phillips screw

Used to fasten metal or plastic to

plastic mainframes.

Threaded Phillips screw with lock and flat washer

Used to fasten metal or plastic to

threaded plastic or metal.

Removal and Replacement Strategy 6-5

Hint To insert self-tapping screws, turn the screw to the left

(counter-clockwise) until it clicks, then turn it to the right (clockwise)

until it is seated. If a self-tapping screw-hole strips, you must repair the

screw-hole or replace the affected assembly.

Long screw (4.8 in/116 mm)

Used to anchor Tray 1 Pickup

Assembly

Table 6-1. Screws Used in the Printer (continued)

Drawing and Description Purpose

6-6 Removing and Replacing Parts

Removing Covers

It is usually best to remove and replace the covers in the order shown.

Turn the printer off and unplug the power cord and any cables.

Hint Left and right are indicated as you face the front of the printer unless

otherwise noted.

Rear Right Side Cover

Figure 6-2 Removing the Rear Right Side Cover

The Formatter and Dual In-line Memory Modules (DIMMs) are

located underneath the Right Side Cover.

1Grasp the cover by its rear lip and pull it firmly toward the rear of

the printer until it stops.

2Remove the cover from the printer.

Removing Covers 6-7

Top Cover

Open the Top Cover and remove the Toner Cartridge.

CAUTION To prevent damage to the Toner Cartridge, do not expose it to light for

more than a few minutes.

To remove the Top Cover, you must remove the Rear Right Side

Cover (page 6-6), the Toner Cartridge Drive Arm (page 6-9), the

Control Panel Overlay (below) and the Control Panel (page 6-8).

Control Panel Overlay

Figure 6-3 Removing the Control Panel Overlay

1Using a flat-blade screwdriver, gently pry upward on the right side

of the Control Panel Overlay to loosen it.

2Remove the Control Panel Overlay from the tabs on the left and

lift it upward, off of the printer.

6-8 Removing and Replacing Parts

Control Panel

Figure 6-4 Removing the Control Panel

1Using a flat-blade screwdriver, pry each side of the Control Panel

upward.

2Remove the top of the Control Panel from the tab.

3Disconnect the ribbon cable from the Control Panel.

Tab

Removing Covers 6-9

Toner Cartridge Drive Arm

Figure 6-5 Removing the Toner Cartridge Drive Arm

1Remove the Toner Cartridge Drive Arm by using needle-nose

pliers to pinch the pin from its hinge on the Top Cover.

Note Be sure to reconnect the Toner Cartridge Drive Arm when you replace

the Top Cover, or the Toner Cartridge will not seat properly.

6-10 Removing and Replacing Parts

Figure 6-6 Removing the Top Cover

2Remove the four screws holding the Top Cover (two are behind

the Rear Output Bin, near the top, and two are on top of the

printer under the Top Cover).

Top screws

Rear screws

Toner cartridge

drive arm

Removing Covers 6-11

Figure 6-7 Releasing tabs to lift the Top Cover

3Squeeze the right front side of the Top Cover to remove it. It may

be necessary to use a small flat-blade screwdriver to release the

tab inside the small hole.

4Holding the output assembly in place (located toward the rear of

the printer), remove the Top Cover.

Release tab if

necessary

6-12 Removing and Replacing Parts

Left Side Cover

Figure 6-8 Removing the Left Side Cover

1Open Tray 1.

2Release the latch on the left side cover from the inside of the

printer. Release the catches on the front side of the cover.

3Lift the cover upward to release the front top side of the cover,

then pull the cover away from the printer.

Latch (inside) Catches

Removing Covers 6-13

Front Right Side Cover

Figure 6-9 Removing the Front Right Side Cover

1Release the latch at the top center of the cover.

2Lift the cover straight up until it is free of the tabs at the bottom

and the power switch rod, then pull it away from the printer.

Hint When you reinstall the Front Right Side Cover, be sure to reconnect

the power switch rod.

Latch

6-14 Removing and Replacing Parts

Rear Cover/Rear Output Bin

Figure 6-10 Removing the Rear Cover/Rear Output Bin

1Facing the rear of the printer, pinch the right side of the Rear

Output Bin and release the hinge from the slot.

2Rotate the bin upward and slide it to the right to release the left

hinge.

Step 1

Step 2

Removing Covers 6-15

Tray 1

Figure 6-11 Removing Tray 1 from the Front Cover

1Open Tray 1.

2Push outward on the two slot hinges to release the pins on Tray 1.

3Slide the Front Cover to the right and remove it from the three

hinges on the bottom.

6-16 Removing and Replacing Parts

Figure 6-12 Removing the Tray 1 Sensor Arm Cover

4Firmly pull both sides of the Tray 1 Sensor Arm Cover toward you

until it releases from the shaft. See Figure 6-13, “Detail of the

Tray 1 Sensor Arm Cover,” on page 6-17.

5Rotate Tray 1 downward and remove it from the two hinges.

Removing Covers 6-17

Figure 6-13 Detail of the Tray 1 Sensor Arm Cover

Hint When you reinstall the Tray 1 Sensor Arm Cover be sure the Sensor

Arms move freely.

6-18 Removing and Replacing Parts

Removing Assemblies

The order in which you replace the following assemblies depends on

the part needing to be replaced. It is not necessary to remove every

assembly.

Fuser

WARNING! Let the Fuser Assembly cool before disassembly.

1Remove the Rear Cover/Rear Output Bin (page 6-14).

Figure 6-14 Removing the Left and Right Duplex Connector Covers

2If a Duplexer is installed, remove it. If a Duplexer is not installed,

remove the Left and Right Duplex Access Covers from the rear of

the printer by pulling each from the bottom.

Removing Assemblies 6-19

Figure 6-15 Loosening the captive screws in the Fuser Assembly

3Loosen the two captive screws on the Fuser Assembly.

4Pull the Fuser Assembly straight out of the printer.

6-20 Removing and Replacing Parts

Formatter Cage Assembly

Figure 6-16 Removing the Formatter Cage Assembly

1Print a Configuration Page. The information is necessary to

reconfigure the printer after you replace the Formatter.

2Remove the rear right side cover (page 6-6). The Formatter Cage

Assembly is directly underneath.

3Remove the captive screw and open the DIMM access door to

see if any DIMMs are installed. Remove and transfer any DIMMs

or EIO accessories if you replace the Formatter.

4Remove the 5 screws around the Formatter cage.

5Slide the Formatter toward the rear of the printer and remove it.

Note Using the Configuration Page you printed in step 1 above, reconfigure

the printer after replacing the Formatter. Be sure to reset the printer’s

page count (page 3-33).

For accessing DIMMs

EIO

accessory

Removing Assemblies 6-21

Output Assembly

Figure 6-17 Removing the Output Assembly

1Remove the Top Cover (page 6-7). The Output Assembly is on

the top, rear of the printer.

Brass arm White tab

6-22 Removing and Replacing Parts

2Facing the rear of the printer, release the 2 latches as follows:

Figure 6-18 Left end of Output Assembly (brass arm)

a On the left end of the assembly, rotate the brass arm up 90°.

Figure 6-19 Right end of Output Assembly (white tab)

b On the right end of the assembly, release the white tab.

3Lift the assembly up and out of the printer.

CAUTION Lift the assembly carefully to avoid damaging the Top Output Bin full

sensor flag. When the assembly is replaced, the flag must be able to

rotate freely.

Removing Assemblies 6-23

Laser Scanner

Figure 6-20 Removing the Laser Scanner

1Remove the Top Cover (page 6-7). The Laser Scanner is on the

top of the printer, tilted toward the rear, and has a yellow label on

it.

2Unplug the 3 connectors as shown.

3Remove the 4 black screws around the edges of the Laser

Scanner. Do not remove the two screws on the cover of the Laser

Scanner.

4Lift the Laser Scanner straight up.

Hint When you replace the Laser Scanner be sure the black shutter interlock

is resting on top of the silver shutter plate.

Shutter interlock and plate

6-24 Removing and Replacing Parts

Fan

Figure 6-21 Removing the Fan

1Remove the Top Cover (page 6-7) and the Left Side Cover (page

6-12). The Fan is on the left side of the printer.

2Unplug the Fan’s connector to the Engine Controller Board.

3Squeeze the latches on the left and right sides of the Fan cover.

4Pull the Fan straight out.

Hint The cover attaches to the Fan at the top right and bottom left corners.

Retain the cover; it is separate from the Replacement Fan.

Removing Assemblies 6-25

Main Motor

Figure 6-22 Removing the Main Motor

1Remove the Top Cover (page 6-7) and the Front Right Side Cover

(page 6-13). The Main Motor is on the right front side of the

printer.

2Unplug the connector.

3Remove the 4 silver screws around the corners of the metal plate.

4Remove the Main Motor from the printer.

6-26 Removing and Replacing Parts

Transfer Roller

Figure 6-23 Removing the Transfer Roller

1Open the Top Cover and remove the Toner Cartridge. The

Transfer Roller is underneath the Toner Cartridge.

CAUTION Do not touch the black rubber part of the roller. Skin oils on the roller

can cause problems with print quality.

2Using a flat-blade screwdriver, pry the right end of the metal shaft

out of place, then the left end.

Hint When you replace the Transfer Roller, make sure the black collar is

oriented properly, with the open end down.

DO NOT TOUCH!

(See Hint)

Removing Assemblies 6-27

Tray 1 Pickup Roller

Figure 6-24 Removing the Pickup Roller (shown with Envelope Entrance Cover

removed)

1Open Tray 1. The Tray 1 Pickup Roller is in the center of the

Tray 1 Pickup Assembly.

2Grasp the Envelope Entrance Cover and pull it straight away from

the printer.

3Pry open the blue latch on the roller.

4Lift the roller out.

Hint To replace the roller, make sure the pin in the roller lines up with the

hole in the shaft.

6-28 Removing and Replacing Parts

Figure 6-25 Detail of the Tray 1 Pickup Roller

Removing Assemblies 6-29

Tray 1 Pickup Assembly

1Remove the covers (starting on page 6-6): Top Cover, Left Side

Cover, Front Right Side Cover, and Tray 1. The Tray 1 Pickup

Assembly is on the front of the printer.

Figure 6-26 Removing the Envelope Feeder Gear Cover

2Flip down or remove the Envelope Feeder Connector Cover.

3Remove the Envelope Entrance Cover.

4Remove the Envelope Feeder Gear Cover as follows:

a Remove the black self-tapping screw at the bottom of the

Envelope Feeder Gear Cover.

b Remove the long screw (4.8 in/116 mm) on the right side of the

Tray 1 Pickup Assembly.

Envelope

feeder

connector

cover

Step 4a

Step 4b

Envelope

feeder gear

cover

6-30 Removing and Replacing Parts

Figure 6-27 Removing the Tray 1 Pickup Assembly – Right Side

5Disconnect the solenoid cable on the right side of the Tray 1

Pickup Assembly. (Note the way the cables are routed for

replacement.)

Removing Assemblies 6-31

Figure 6-28 Removing the Tray 1 Pickup Assembly – Left Side

6Unplug the connector to the Engine Controller Board on the left

side of the Tray 1 Pickup Assembly.

7Remove the long screw (4.8 in/116 mm) from the left side of the

assembly.

8Remove the self-tapping screw shown.

Step 6

Step 7

Step 8

6-32 Removing and Replacing Parts

Figure 6-29 Removing the Tray 1 Pickup Assembly – Front Side

9Remove the 3 screws shown.

10 Lift the black Toner Cartridge Guide on the right side of the

assembly and pull the assembly straight out of the printer. See

page 6-33 for the procedure.

Toner

cartridge

guide

Removing Assemblies 6-33

Right Side Toner Cartridge Guide

You can lift aside the Right Side Toner Cartridge Guide (instead of

removing it) to access the Registration Assembly. It is not necessary

to unplug the connectors.

Remove the Right Side Toner Cartridge Guide to access the Gear

Train. Follow the steps below:

1Remove the Top Cover (page 6-7), Front Right Side Cover (page

6-13), and Tray 1 (page 6-15). The Right Side Toner Cartridge

Guide is on the right front side of the printer.

Figure 6-30 Removing the Right Side Toner Cartridge Guide

2Remove the black self-tapping screw.

3Unplug the 3 connectors if necessary.

4Remove the small silver screw to disconnect the ground wire.

5Lift the Right Side Toner Cartridge Guide off the printer.

Step 2

Step 3

Step 4

6-34 Removing and Replacing Parts

Registration Assembly

Figure 6-31 Removing the Registration Assembly

1Remove the following covers (starting on page 6-6): Top Cover,

Left Side Cover, Front Right Side Cover, and Tray 1. Remove the

Tray 1 pickup assembly (page 6-29). The Right Side Toner

Cartridge Guide can be lifted without removal (page 6-33). The

Registration Assembly is under the Toner Cartridge.

2Remove the 3 black self-tapping screws shown. (Lift the green

handle on the right end of the Registration Assembly to access

the black screw on the left rear side.)

Removing Assemblies 6-35

Figure 6-32 Detail of screws for the Registration Assembly

CAUTION Do not remove the silver screw closest to the Registration Assembly!

It holds the spring in place. Take out the silver screw farther from the

registration assembly, the one that is under the green handle.

3Lift the green handle. Remove the 2 black self-tapping screws

and the rearmost silver screw shown. See the caution above.

Hint If the Anti-static Bar becomes displaced, reinstall it with the left end in

the slot, or paper may jam in this area.

DO NOT REMOVE!

6-36 Removing and Replacing Parts

Paper Feed Assembly

1Remove the following covers (starting on page 6-6): Top Cover,

Left Side Cover, Front Right Side Cover, and Tray 1. Remove the

Tray 1 Pickup Assembly (page 6-29). The Paper Feed Assembly

is on the front of the printer.

Figure 6-33 Unplugging the connector to the Paper Feed Assembly

2Unplug and unroute the 2-pin connector from the right side.

CAUTION For replacement of the Paper Feed Assembly, note the way the wires

are routed to the connector. If a wire is routed improperly, it can be

damaged.

Note

routing

Removing Assemblies 6-37

Figure 6-34 Removing the upper screws from the Paper Feed Assembly

3Remove the 2 black upper screws.

Hint After replacing the Paper Feed Assembly, make sure to insert the 2

upper screws only. The 2 lower screws are for holding the Tray 1 Pickup

Assembly in place.

6-38 Removing and Replacing Parts

Hint For replacement of the Paper Feed Assembly, orient the clutch properly

by inserting it into the slot, as shown.

Figure 6-35 Detail of the Paper Feed Clutch

Removing Assemblies 6-39

Formatter Pan

Figure 6-36 Removing the Formatter Pan

1Remove the Top Cover (page 6-7) and the Front Right Side Cover

(page 6-13). Remove the Formatter Cage Assembly (page 6-20).

The Formatter Pan is on the right rear side. Remove the

Formatter Pan in order to split the engine from the tray assembly

or to access the Gear Train.

2Remove the 4 black self-tapping screws.

3Remove the 3 silver M-3 screws.

4Pull the Formatter Pan straight out, away from the printer.

6-40 Removing and Replacing Parts

Gear Train

Figure 6-37 Removing the Gear Train

1Remove the following covers (starting on page 6-6): Top Cover,

Front Right Side Cover, Rear Cover/Rear Output Bin, and Tray 1.

Remove the Right Side Toner Cartridge Guide (page 6-33), the

Registration Assembly (page 6-34), the Formatter Cage

Assembly (page 6-20), and the Formatter Pan (page 6-39). The

Gear Train is on the right side of the printer.

2If the Registration Assembly has not already been removed, take

out the rearmost silver screw under the green handle (page

6-35).

3Remove the 8 black self-tapping screws.

4Pull the Ribbon Cable Assembly outward (off the pin), then down,

out of the way.

5Remove any remaining wires from the white plastic guide.

6Slide out the Gear Train.

Note When you reinstall the Gear Train, slide the top in first and then push

the bottom in.

Step 4

Toner Cartridge Drive Arm

Removing Assemblies 6-41

Delivery Drive Assembly

Figure 6-38 Removing the Delivery Drive Assembly

1Remove the covers (starting on page 6-6): Top Cover, Left Side

Cover, Front Right Side Cover, Rear Cover/Rear Output Bin, and

Tray 1. Remove the Output Assembly (page 6-21), Formatter

Cage Assembly (page 6-20), Formatter Pan (page 6-39), and

Fuser Assembly (page 6-18). The Delivery Drive Assembly is on

the right rear side of the printer.

2Remove the single screw.

3Unplug the 3-pin connector shown.

4Lift the Delivery Drive assembly upward, away from the printer.

6-42 Removing and Replacing Parts

Separating the Engine Module from the

Paper Feed Module

This procedure is the same for printers with a single 500-sheet Tray or

two 250-sheet Trays.

1Remove the Rear Right Side cover (page 6-6). Remove the

Formatter Cage Assembly (page 6-20), Formatter Pan (page

6-39), and 2 long screws from the Tray 1 Pickup Assembly (See

Figure 6-26 on page 6-29 and Figure 6-28 on page 6-31).

Figure 6-39 Unplugging the connector to the Paper Feed Module

2Unplug the connector to the Paper Feed Module on the right rear

side of the printer (under the formatter pan). Remove the cable

from its bracket.

Separating the Engine Module from the Paper Feed Module 6-43

Figure 6-40 Separating the Engine from the Paper Feed Module

3Remove the single black, self-tapping screw from the left side of

the printer, below the Fan.

CAUTION Lift the Engine carefully, being sure that all cables are disconnected.

4Lift the Engine away from the Paper Feed Module.

6-44 Removing and Replacing Parts

Engine Controller Board

Note After you replace the Engine Controller Board, do not forget to readjust

the top margin as described on page 6-46.

1Separate the Engine from the Paper Feed Module (page 6-42).

The Engine Controller Board is on the underside of the Engine

and contains the following:

• DC controller

• High-voltage power supply

• AC power supply

• DC power supply

• Timing controls

Figure 6-41 Removing the Engine Controller Board

2Remove the Fuser Assembly (page 6-18).

Spring

Power

switch

rod

(In the back, not on the board)

Separating the Engine Module from the Paper Feed Module 6-45

Facing the front of the Engine Module:

3Remove 7 screws (shown in Figure 6-41 on page 6-44):

• 4 black, self-tapping M4 screws (3 in front and 1 in the right

rear)

• From the left rear, 3 M3 screws (1 recessed)

4Disconnect the spring on the right side from the notch.

5Disconnect the Power Switch Rod.

Figure 6-42 Removing the Engine Controller Board

6Lifting from the printer’s left side (the side the Fan is on), tip the

board up, then unplug all connectors.

Hint The black cable router in the middle of the Engine Controller Board can

be folded aside with the cables intact. When you replace the board,

reconnect and route all cables before reconnecting the power switch

rod.

Be sure to reconnect the spring on the right side to the Ground Plate.

6-46 Removing and Replacing Parts

Adjusting the Top Margin

When you replace the Engine Controller Board, you must readjust the

top margin as follows:

Figure 6-43 Location of VR501

1After setting the VR501 on the Engine Controller Board to the

center position (0), load letter or A4 paper in the tray. Press the

Engine Test Print Button (located on the left side of the printer,

below the vent) to make several test prints.

Separating the Engine Module from the Paper Feed Module 6-47

Figure 6-44 Adjusting the top margin

2Measure the distance between the edge of the paper and the

print pattern. Measure all the test prints and calculate the

average.

3Adjust VR501 so that the margin becomes .08 in (2 mm). Turn

VR501 clockwise to decrease the margin or counter-clockwise to

increase the margin.

4Make several test prints again and perform step 2 above. If the

top margin is still incorrect, repeat the procedure.

Measure this distance

6-48 Removing and Replacing Parts

Paper Feed Rollers

The following procedure is the same for all HP LaserJet 4000 and

4050 series printers; there are 2 Feed Rollers for the HP LaserJet

4000 T/4000 TN and 4050 T/4050 TN and one Feed Roller for the

HP LaserJet 4000/4000 N and 4050/4050 N printers.

Figure 6-45 Removing the Paper Feed Rollers (HP LaserJet 4000 T/4000 TN and

4050 T/4050 TN shown)

1Remove the tray(s) from the Feeder. The Paper Feed Rollers are

inside the Feeder.

2Pinch the release at the left side of the Roller and slide it off the

shaft.

Separating the Engine Module from the Paper Feed Module 6-49

Separation Rollers

Figure 6-46 Removing the Separation Rollers

The Separation Rollers are inside the paper trays.

1Release the latch and lift the cover inside the tray.

2Pinch the release at the left side of the Roller and slide it off the

shaft.

6-50 Removing and Replacing Parts

Paper Feed Module Plate

Remove the Paper Feed Module Plate to access the Controller PCA.

This procedure is the same for one 500-sheet Tray or two 250-sheet

Trays.

Figure 6-47 Removing the Paper Feed Module Plate

1Remove the 7 black self-tapping screws (one of them is recessed

in front).

2Remove 2 small metal-to-metal screws.

3Lift up the Paper Feed Module Plate to remove it.

(Small)

Separating the Engine Module from the Paper Feed Module 6-51

Paper Feed Module Gear Train Assembly

This procedure is the same for one 500-sheet Tray or two 250-sheet

Trays.

Figure 6-48 Removing the Gear Train

1Remove the long recessed screw shown.

2Unplug the connector (note routing).

3Lift the gear train upward, away from the Paper Feed Module.

Unplug

connector

6-52 Removing and Replacing Parts

Paper Feed Module Side Rails

Remove the Paper Feed Module side rails to access the PCA

Controller. This procedure is the same for one 500-sheet Tray or two

250-sheet Trays.

Figure 6-49 Removing the Paper Feed Module side rails (HP LaserJet

4000 T/4000 TN and 4050 T/4050 TN shown)

1To remove the side rails, remove the 4 recessed screws (1 is

long).

2Unplug the connector.

3Lift the side rails off of the Paper Feed Module.

Unplug

connector

(Long

screw)

Separating the Engine Module from the Paper Feed Module 6-53

Lower Paper Feed Module Plate (HP LaserJet

4000 T/4000 TN and 4050 T/4050 TN)

Figure 6-50 Removing the lower Paper Feed Module Plate

1Remove 9 black self-tapping screws.

2Remove 2 small black M3 screws.

3Lift up the lower Paper Feed Module Plate to remove it.

6-54 Removing and Replacing Parts

PCA Cover (HP LaserJet 4000 T/4000 TN and

4050 T/4050 TN)

Figure 6-51 Removing the PCA Cover (HP LaserJet 4000 T/4000 TN and

4050 T/4050 TN)

1Pinch the left and right sides of the PCA Cover to release it from

the side latches.

2Rotate the PCA Cover downward and toward you to remove it.

Separating the Engine Module from the Paper Feed Module 6-55

PCA Cover (HP LaserJet 4000/4000 N and

4050/4050 N)

Figure 6-52 Removing the PCA Cover (HP LaserJet 4000/4000 N and

4050/4050 N)

1Release the latches shown.

2Remove the PCA Cover.

6-56 Removing and Replacing Parts

PCA Controller

This procedure is the same for one 500-sheet Tray or two 250-sheet

Trays.

Figure 6-53 Removing the PCA Controller

1Unplug 3 connectors to the PCA Controller.

2Unclip the left side of the PCA Controller and remove it.

Overview 7-1

7Troubleshooting

Overview

This chapter discusses the following:

●Troubleshooting Process

●Troubleshooting the Printing System

●Reference Diagrams

7-2 Troubleshooting

Troubleshooting Process

The troubleshooting process is a systematic approach that addresses

the major problems first, and then other problems as you identify the

causes for printer malfunctions and errors. The “Troubleshooting

Flowchart” on page 7-4 illustrates the major steps for troubleshooting

the printing system. 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.

The following list describes the basic questions for the customer and

the corresponding troubleshooting step to help you quickly define the

problem(s).

Table 7-1. Major Steps for Troubleshooting

Power On

(page 7-7) Does the printer perform the initialization and power-on steps?

This section gives the procedures for correcting power supply

problems.

Display

(page 7-12) Does the Control Panel indicate READY

, OFFLINE, or

POWERSAVE ON?

This section gives the procedures for clearing Control Panel error

messages and displaying and correcting Event Log codes.

Event Log

(page 7-13) Are there recurring problems in the Event Log?

This section gives information about printing the Event Log and

evaluating the error history.

Printer Messages

(page 7-17) Does the printer’s Control Panel display an error message?

This section provides an alphabetical and numerical listing of the

printer’s Control Panel messages, and gives the recommended

actions to resolve the problem.

Troubleshooting Process 7-3

General Paper Path

Troubleshooting

(page 7-45)

Is there a paper jam in the printer?

This section gives information about solving problems in the

paper path.

Information Pages

(page 7-48) Will the printer print information pages successfully?

This section gives the procedures for printing the information

pages and evaluating and correcting the printer’s configuration.

Image Quality

(page 7-54) Does the print quality meet the customer’s expectations?

This section gives Toner Cartridge checks, information on

EconoMode, image defect examples, and the Repetitive Defect

Ruler.

Interface Troubleshooting

(page 7-77) Can the customer print from the host system successfully?

This section describes how to determine if the printer is

communicating properly with the host system.

Table 7-1. Major Steps for Troubleshooting (continued)

7-4 Troubleshooting

Troubleshooting Flowchart

Figure 7-1 Troubleshooting Flowchart (1 of 2)

Troubleshooting Process 7-5

Troubleshooting Flowchart (Continued)

Troubleshooting Flowchart, continued

7-6 Troubleshooting

Troubleshooting the Printing System

Preliminary Operating Checks

Prior to troubleshooting a specific printer problem, you should ensure

that:

●The printer is being maintained on a regular basis as described in

Chapter 4.

●The customer is using acceptable paper as specified in the

HP Printer Family Paper Specification Guide

●The printer is positioned on a solid, level surface.

●The line voltage does not vary more than 10% from the nominal

rated value as specified on the Power Rating Label.

●The operating environment for the printer and paper is within the

temperature and humidity specifications listed in Chapter 1 of this

manual.

●The printer is never exposed to ammonia fumes such as those

produced by diazo copiers or office cleaning materials.

●The printer is not exposed to direct sunlight.

●Non-HP components (such as refilled Toner Cartridges, font

cartridges, and memory boards) are removed from the printer.

Note When moving the printer into a warm room from a cold location such

as a warehouse, various problems can occur due to condensation in

the printer. For example, if the Photosensitive Drum is cold, the

resistance of the photoconductive layer will be high. This will lead to

incorrect contrast. Leave the printer running for 10 to 20 minutes.

Troubleshooting the Printing System 7-7

Power On

Note It is important to have the printer’s Control Panel functional as soon as

possible in the troubleshooting process so that the printer’s diagnostics

can assist in locating printing errors.

Table 7-2. Power On Defect or Blank Display

Problem Action

Is the power cord plugged

into the wall and the

printer? Is AC and DC

power available?

Verify. See Table 7-3, “No AC Power,” on page 7-9 and Table 7-4,

“No DC Power,” on page 7-10.

Is the power switch set to

on? Set the switch to the on position. You should hear the switch

toggle. If the Front Right Side Cover has been removed recently,

be sure that the rod leading to the power supply moves as the

rocker switch is toggled.

7-8 Troubleshooting

Note The Fan only operates during initial power on and while printing, unless

the temperature inside the printer is too high. If the temperature is too

high, the Fan turns on to cool the inside of the printer.

Does the Fan turn on for

about 4 seconds when you

first turn the printer on?

Note: Fan operation is significant since the Fan is controlled by

the printer’s Engine Controller Board. An operational Fan

indicates the following:

1. AC power is present in the printer.

2. DC power supply is functional (both 24VDC and 3.5VDC are

being generated).

3. The Engine Controller Board’s micro-processor is functional.

If the Fan is not working:

1. Turn the printer off and remove the printer’s Formatter PCA.

Disconnect all the printer’s Paper Handling Options.

2. Turn the printer on and check the Fan again.

If the Fan is still not working, perform the following steps:

1. Verify that the fan is connected to the Engine Controller Board.

2. Replace the Fan.

3. Replace the Engine Controller Board.

If the Fan is working but the printer’s Control Panel is blank:

1. Print an Engine Test. See “Engine Test” on page 7-11.

If the Engine Test is successful, perform the following steps:

a. Reseat the Control Panel and Formatter Connector.

b. Replace the Control Panel Assembly.

c. Replace the Formatter.

d. Replace the cable from the Control Panel.

2. If the Engine Test is not successful, replace the Engine

Controller Board.

Table 7-2. Power On Defect or Blank Display (continued)

Problem Action

Troubleshooting the Printing System 7-9

Table 7-3. No AC Power

Cause Action

No correct voltage present at the outlet. Plug the power cord into another AC circuit

outlet.

Inform the customer that the correct line

voltage is not available at the outlet.

The power cord is not firmly plugged into the

printer and the outlet. Insert the power plug firmly.

Blown fuse. 1. Check the fuses (FU1 and FU2) on the

Engine Controller Board.

2. Replace the fuses if necessary.

Defective power switch. Remove the Engine Controller Board.

Measure the resistance between the two

terminals of the power switch (SW1) by

applying the tester probes to the terminals.

The resistance must be low (under 1KΩ) when

the power is turned ON, and high (over 6MΩ)

when the Switch is turned OFF. Otherwise,

replace the Engine Controller Board.

Defective AC receptacle or AC power line. Check the printer’s AC receptacle and wiring

for the AC power line. If no problem is found,

replace the Engine Controller Board.

7-10 Troubleshooting

Table 7-4. No DC Power

Cause Action

No AC power is supplied. Check the AC power supply. See Table 7-3,

“No AC Power,” on page 7-9

The overcurrent/overvoltage detection circuit

activated. If the problem is not rectified after the power

switch is turned off and on again, find the

cause of activation of the

overcurrent/overvoltage detection circuit in the

power supply. Wait for more than two minutes

before turning the printer back on.

Blown fuse. 1. Check the fuses (FU1 and FU2) on the

Engine Controller Board.

2. Replace the fuses if necessary.

Troubleshooting the Printing System 7-11

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

left side of the printer (see Figure 7-2 on page 7-12). 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 PCA is completely bypassed during an Engine Test)

●Is used for isolating printer problems

●Is used for checking and adjusting registration

●Prints from Tray 2, 3, or 4 only, not from Tray 1

●Can be activated with the Formatter PCA removed

Note For the printer to perform an Engine Test, Tray 2, 3, or 4 must be

installed and loaded with paper, and the Toner Cartridge must be

installed in the printer.

Location of Engine Test Button

The Engine Test button is located on the left side of the printer, below

the Fan vent, as shown in Figure 7-2 on page 7-12.

7-12 Troubleshooting

Figure 7-2 Location of the Engine Test Button

Printing an Engine Test

To print an engine test, use a non-metallic object (such as a pencil) to

press the engine test button. A single test page with vertical lines

prints. To print multiple test pages, hold down the engine test button.

Display

The Control Panel should display READY

, OFFLINE, or POWERSAVE ON.

For information about errors displayed, access the Event Log (see

page 7-13). If the display is blank, see page 7-7.

Troubleshooting the Printing System 7-13

Event Log

Use the Event Log to diagnose and troubleshoot printer errors and

intermittent failures. You can either display or print the Event Log.

Access the Event Log from the Control Panel’s Information Menu.

(Select PRINT EVENT LOG or SHOW EVENT LOG.) The Event Log

retains the printer’s last 30 error messages.

See the tables starting on page 7-18 for more information about

correcting Event Log messages in the printer.

Note LJ4000 Only: The Event Log codes and the error on the Control Panel

do not always correspond exactly. The numbers in the Control Panel

message may not be the same in the Event Log; the decimal numbers

may be shifted by one digit. For example, 13.1 on the Control Panel

reads 13.01 in the Event Log. Refer to the correct number in the tables

starting on page 7-18.

7-14 Troubleshooting

Figure 7-3 Sample Event Log

Most recent error

(up to 30)

Troubleshooting the Printing System 7-15

Display the Event Log

If the printer cannot print or move any paper, follow these steps to

display the Event Log. Otherwise, print the event log.

1Press [Menu] until INFORMATION MENU appears.

2Press [Item] until SHOW EVENT LOG appears.

3Press [Select] to show the Event Log.

4Press [+] to scroll through the Event Log.

5Write down the error messages.

6Check the Event Log for specific error trends in the last 10,000

printed pages.

7Ask the customer for any observed error trends. (For example, do

paper jams tend to occur in a specific area of the printer?)

8Record any specific error trends.

9See Table 7-5, “Alphabetical Printer Messages,” on page 7-18 or

Table 7-6, “Numerical Printer Messages,” on page 7-29 and follow

the recommended action.

10 If the Control Panel displays READY

, OFFLINE, or POWERSAVE ON,

go to the next section. If it displays any other message, repeat

this procedure starting from step 1.

Print the Event Log

The printer’s internal Event Log stores the last 30 errors and can be

printed at any time. To print the Event Log:

1Press [Menu] until INFORMATION MENU appears.

2Press [Item] until PRINT EVENT LOG appears.

3Press [Select] to print the Event Log.

7-16 Troubleshooting

Interpret the Event Log

The Event Log is the key tool in troubleshooting printer problems.

Figure 7-3 shows a typical Event Log. The Event Log shows the

current page count at the top left of the page with the printer’s serial

number directly to the right of the page count. The left column is the

error sequence number, with the error listed at the top (the highest

sequence number is the most recent error logged). The next column

is the page count at the time of the error, and the last column is the

Personality (PCL or PostScript) column or the cause of the jam at the

time of the error.

The event log for early versions of the HP LaserJet 4000 series

printer may record errors in a different format than the Control Panel

display. For example, if 13.20 PAPER JAM is displayed on the Control

Panel, the Event Log records error number 13.32.48 or 13.20.48.

Hint Whenever a 13.XX appears on the Control Panel, a good practice is to

clear the jammed paper from the printer and print the Event Log. If you

cannot print the Event Log, you can still display it on the Control Panel.

Write the error next to the last error logged. The last error is the error

at the top of the Event Log printout with the highest number in the

left-most column.

To interpret the Event Log:

●Each individual entry in the log is called an “error,” while all errors

occurring at the same page count are called an “event.” Read the

Recommended Action for each error comprising an event to gain

a clear picture of what took place during that event. Events

usually conclude with a time-out, or no response from device

(error 66.XX in the Event Log) which requires a power cycle of the

print engine.

●Use the Event Log table in this section to associate errors in the

Event Log with the Control Panel error message. Follow the

recommended action listed in the table for each error or event.

Troubleshooting the Printing System 7-17

Printer Messages

The following tables explain messages that might display on the

printer’s Control Panel. Alphabetical printer messages and their

meanings are listed in Table 7-5, and numerical printer messages are

listed in Table 7-6.

Hint If a message persists requesting that you load a tray, or if a message

indicates that a previous print job is still in the printer’s memory, press

[Go] to print or press [Cancel Job] to clear the job from the printer’s

memory.

Note Not all messages are described (many are self-explanatory).