Powerwave Technologies 5JS0056 Multi Carrier RF Power Amplifier User Manual 273681
Powerwave Technologies Inc Multi Carrier RF Power Amplifier 273681
Contents
Manual 6
G3S-800-140-031 Installation & Service Manual
Copyright Powerwave Technologies, Inc., September 2001. All rights reserved
044-05095 Rev. A 6-1 September 2001
Section 6 Troubleshooting
6-1 Introduction
This section contains a list of problems and a few suggested actions that may correct the prob-
lem. If the suggested corrective action does not eliminate the problem, please contact your Pow-
erwave field representative or the factory for further instructions.
NOTE
Check your sales order and equipment warranty before attempting to service or repair
the unit. Do not break the seals on equipment under warranty or the warranty will be
null and void. Do not return equipment for warranty or repair service until proper
shipping instructions are received from the factory.
6-2 Troubleshooting
The following are general guidelines established to aid Field Engineers or Cell Site Technicians
in the proper method of Powerwave equipment fault resolution by fault mode.
6-2.1 DC Voltage Indicators Not Illuminated
1. Check the front panel ON/OFF switch.
2. Check the power plant circuit breaker.
3. Check for +27 + 1.0 VDC at the amplifier subrack input.
A. If the voltage is low, verify that all DC connections between the power plant and the
amplifier subrack are tight.
B. If the voltage is correct,
1. Remove the amplifier from the subrack slot and move the amplifier to another am-
plifier subrack slot.
2. Check the voltage on the power pins of the mating amplifier and amplifier subrack
connector.
3. Verify that the amplifier DC connections are not damaged.
4. Return the amplifier to the factory for repair.
6-2.2 OVER PWR Illuminated or Blinking
1. If all the amplifiers in a given amplifier subrack are in Over Pwr and the LPA Disable LED is
illuminate, then the input RF power level is too high and the amplifiers have been turned off.
RF power may be incorrectly set during equipment commissioning. This may be due to a
faulty jumper cable. Verify the amplifier subrack output cables, transmit filter, and directional
coupler are in proper working order. The loss between the amplifier subrack and the hatch
plate is typically less than 2.0 dB.
2. If all the amplifiers in a given amplifier subrack are in Over Pwr and the LPA Disable LED is
not illuminated, then the input RF power level is too high. The amplifier subrack is attempting
to maintain a safe power output level (smart subracks with True RMS power detectors and
voltage variable attenuators only). RF power may be incorrectly set during equipment com-
missioning. This may be due to a faulty jumper cable. Verify the amplifier subrack output ca-
bles, transmit filter, and directional coupler are in proper working order. The loss between
the amplifier subrack and the hatch plate is typically less than 2.0 dB.
G3S-800-140-031 Installation & Service Manual
Copyright Powerwave Technologies, Inc., September 2001. All rights reserved
044-05095 Rev. A 6-2 September 2001
3. If only one or two amplifiers in a given amplifier subrack are in Over Pwr and the LPA Dis-
able LED is blinking, then the amplifier subrack is probably in Sleep Mode (smart subracks
with True RMS power detectors and voltage variable attenuators only).
A. Pressing the On/Off/Reset switch momentarily in the Up position or cycling DC power
on the amplifier should bring the amplifier back on-line.
B. Sleep Mode firmware may be disabled in the field with a PC interface and software
available from Powerwave.
4. Move the amplifier to another slot in a different subrack, if available. Mark the amplifier with
a sticker or place a tie wrap on the handle to identify the amplifier. Monitor for future failure.
A. If the same amplifier fails again, return the amplifier to the factory for repair.
B. If the replacement amplifier in the original subrack fails, replace the amplifier subrack.
6-2.3 HIGH TEMP Illuminated
5. If an amplifier is in HIGH TEMP and the LPA Disable LED is illuminate, then the amplifier
heat sink temperature is too high. This may be due to:
A. High ambient temperature.
B. Fan failure.
C. Insufficient air-volume capacity. Most of Powerwave’s amplifiers require a certain
amount of free-space to allow proper airflow.
6. Correct the heat problem, then reset the amplifier by momentarily pressing the Reset button
on the amplifier front panel up.
6-2.4 VSWR Illuminated
7. If all the amplifiers in a given amplifier subrack are in VSWR and the LPA Disable LED is il-
luminate, then the output RF reflected power level is too high and the amplifiers have been
turned off. This may be due to a faulty jumper cable or transmit filter. Verify the amplifier
subrack output cables, transmit filter, and directional coupler are in proper working order.
The loss between the amplifier subrack and the hatch plate is typically less than 2.0 dB. This
fault normally occurs during site or just following site power setting and normally takes about
10 to 15 minutes to reveal itself. This fault may not occur at low power levels (i.e. when just
one or two channels are up).
8. If one amplifier in an amplifier subrack is in VSWR and the LPA Disable LED is illuminated,
then the output RF reflected power level is too high for that amplifier. This may be due to
A. A damaged or recessed amplifier RF output connector. Return the amplifier to the fac-
tory for repair.
Mishandling of the amplifier normally causes recessed pins. Before installing an ampli-
fier, look at the D-sub connector to ensure none of the pins are recessed, bent or that
the outer connector shield is not damaged. When installing the amplifier, do not force
the amplifier into the slot. Gentle even pressure is all that is needed to properly seat the
amplifier.
B. Improper seating of the amplifier.
1. Ensure the amplifier thumbscrews are properly tightened.
2. Try seating the amplifier in another subrack slot.
3. Try seating the amplifier in a subrack in another sector.
6-2.5 DC FAIL Illuminated
G3S-800-140-031 Installation & Service Manual
Copyright Powerwave Technologies, Inc., September 2001. All rights reserved
044-05095 Rev. A 6-3 September 2001
If an amplifier is in DC FAIL and the LPA Disable LED is illuminate, then one of the four amplifier
DC voltages is either out of tolerance or not present. Return the amplifier to the factory for repair.
6-2.6 FAN FAIL Illuminated
If an amplifier is in FAN FAIL, then the one of the amplifier’s cooling fans has failed. Replace the
fan.
Fan failure does not cause the amplifier to shut down; amplifier shut down is determined by heat
sink temperature.
6-2.7 LOOP FAIL Illuminated
9. Loop Fail is always accompanied by LPA Disable LED illuminated. This may be due to
A. Inability of the amplifier to maintain a 180° phase shift between the first and second
loops.
B. A damaged error amplifier. This can be caused by
1. Out of band spurious or intermods being applied at too high of a level at the ampli-
fier input port. An input band-pass filter may be necessary to correct this problem.
2. Disconnecting amplifier RF output cables while the amplifier is still turned on. Al-
ways turn the amplifier off when moving output RF cables from the hatch plate to
test equipment and back again.
C. Improper power balance between amplifiers in a given subrack.
1. Ensure the amplifier thumbscrews are properly tightened. Reset the amplifier by
momentarily pressing the Reset button on the amplifier front panel up.
2. Try seating the amplifier in another subrack slot.
3. Try seating the amplifier in a subrack in another sector.
6-2.8 LOW PWR Illuminated
Low Power is always accompanied by the LPA Disable LED illuminated. This is due to the gain of
either the internal preamplifier or main amplifier being 0.5 dB (typically) or more below the ampli-
fier specification. The amplifier should be returned to the factory.
6-2.9 LPA DISABLE Illuminated
10. LPA Disable LED illuminated indicates that the amplifier RF section is turned off. This may
be due to
A. An accompanied alarm indicating a critical amplifier fault (i.e. Loop Fail fault).
B. A response to a subrack command, purposely inhibiting the amplifier (i.e. Sleep Mode
activation)
C. Improper seating of the amplifier in the subrack.
11. Ensure the amplifier thumbscrews are properly tightened. Reset the amplifier by momentar-
ily pressing the Reset button on the amplifier front panel up.
12. Try seating the amplifier in another subrack slot.
13. Try seating the amplifier in a subrack in another sector.
6-3 Return For Service Procedures
G3S-800-140-031 Installation & Service Manual
Copyright Powerwave Technologies, Inc., September 2001. All rights reserved
044-05095 Rev. A 6-4 September 2001
When returning products to Powerwave, the following procedures will ensure optimum response.
6-3.1 Obtaining An RMA
A Return Material Authorization (RMA) number must be obtained prior to returning equipment to
the factory for service. Please contact our Repair Department at (888) 797-9283 or (714) 466-
1000 to obtain this number, or FAX your request to (714) 466-5816. Failure to obtain this RMA
number may result in delays in receiving repair service.
6-3.2 Repackaging For Shipment
To ensure safe shipment of the amplifier, it is recommended that the package designed for the
amplifier be used. The original packaging material is reusable. If it is not available, contact
Powerwave’s Customer Service Department for packing materials and information.