Lexmark T632 Service Manual page 113

Measure all voltages from the connector to printer ground. All voltages measured during the print
cycle are measured with the controller board removed while running the print test.
Print quality—all black page
Service tip: An all black page is generally caused by a problem in the high voltage system or an
incorrect high voltage in the printing process resulting in toner development on the entire
photoconductor drum.
FRU
1 High voltage contacts
2 Charge roll conductive
bushing
3 HVPS
4 HVPS cable
(part of front
harness cable)
System board
Print quality—blank page.
FRU
1 Print cartridge
2
High voltage contact
3 HVPS
4 Front cable harness HVPS
section
Printhead assembly
5
Action
Check the high voltage contacts on the right side frame to ensure
they fit securely and are not pitted, contaminated, or damaged. If
incorrect, replace the contact with one from the HV contact kit.
Screws are included to attach the contacts to the right side frame in
the HV contact kit.
Make sure the charge roll bushing is correctly installed in the right
charge roll arm.
Check the voltages on J22-1 thru J22-8. If incorrect, replace the
system board.
Check the continuity of the HVPS cable. If incorrect, replace the
cable assembly. If correct, replace the system board.
Action
Check the print cartridge for damage, especially the PC drum contact
on the cartridge.
Check the PC drum contact on the right side frame for damage, PC
drum contact wear or contamination. If the contact is bent or
damaged, replace the contact.
Note: Inspect the HVPS PC drum contact on the board for damage
or contamination.
Check the fuse on the HVPS. If open, replace the HVPS. Check the
voltages at J22 on the system board. Measure the following voltages
from connector J22 to printer ground:
• Printer Idle
J22-5 measures +24 V dc
• Printer Printing
J22-5 measures +24 V dc
If the voltages at J10-5 are incorrect, replace the system board.
Check the front cable harness at J22 on the system board and at
CN1 on the HVPS to make sure the harness is connected properly. If
connected properly, check the continuity of the cable harness. If there
is no continuity, replace the front cable harness.
Generally a 93x service error is posted if the printhead assembly fails
and the printer does not give a blank copy symptom.
The printhead used in the printer does not have a mechanical shutter
as previous laser printers. The printer is interlocked through the front
top cover interlock switch.
4060-xxx
Diagnostic information
2-79