Lexmark T620 Service Manual page 146

4069-5XX/7XX
FRU
2 Charge Roll Assembly
Charge Roll Link Arm
3 HVPS
2-118
Service Manual
Action
Check the charge roll for any signs
of toner buildup or other
contamination on the outer edges
that correspond to the bands on the
page. Check the charge links and
arms for proper operation, binds or
incorrectly mounted counterbalance
springs. Repair or replace as
necessary.
Check the following voltages at
J25-8 on the system board:
Printer Idle
J25-8 measures 0 V dc
Printer Printing Test Page
J25-8 voltage changes from 0 V dc
to +4 V dc
If the voltage does not vary, check
the continuity of line J25-8 in the
front cable harness. If there is no
continuity, replace the cable
harness. If there is continuity,
replace the HVPS. If this does not
correct the problem, replace the
system board.
Turn the printer off and check the
resistance between J25-7 and
printer ground. The resistance
measures approximately 0 ohms. If
incorrect, make sure the system
board is mounted correctly and
securely grounded. If correct,
replace the system board.