Black Only Retract (Bor) Service Check - Lexmark C78x Service Manual

5061
Step D
Step Actions and questions
1 Enter the Diagnostics Mode and select INPUT TRAY
TESTS, Sensor Test, and Tray 1. You can activate
the paper level sensor inside the printer. The paper
level sensor is a dual sensor and checks the following
levels for Tray 1.
The Tray 1 level sensor is a dual sensor assembly that
senses when tray 1 is empty, nearly empty, or partially
empty.
Does the Sensor Test pass?
2 Paper level sensing assembly—Make sure the
assembly is not loose or damaged. Make sure the
bellcrank is not broken.
Are any parts loose or broken?
3 Check the paper level sensing cable for correct
installation at JTRAY1 on the system board and to the
paper level sensing dual sensor assembly.
Is the cable connected correctly?
4 Check the paper level sensing assembly flag for
correct installation and that the flag is not broken or
damaged.
Is the paper level sensing assembly installed correctly
and the flag not broken or damaged?
5 Check continuity of the paper level sensing cable.
Is there continuity?
6 Check the voltage at JTRAY1. It should measure
approximately +5 V dc.
Is the voltage correct?

Black only retract (BOR) service check

Step Actions and questions
1 Using the toggle ITU function in diagnostics mode, test
the BOR system. Remove the print cartridges, and
watch the belt while activating the toggle function.
Does the ITU belt move up and down when the ITU is
toggled?
2 Remove the ITU. Locate the BOR gear, and manually
activate the gear. Verify that the front and back BOR
cams are moving the respective bell cranks.
Do the cams move back and forth properly?
2-80
Service Manual
Yes No
Contact your next Go to step 2
level of support.
Repair or replace Go to step 3
parts as
necessary.
Go to step 4 Install the cable
correctly.
Go to step 5 Install correctly or
replace the flag if
damaged or
broken.
Go to step 6 Replace the level
sensing cable.
Replace the level Replace the
sensing system board.
assembly. See
board removal"
on page
Yes No
Go to "Print Go to step 2
quality service
check" on
page 2-95.
Replace in the Determine which
following order: component is
preventing the
1. "BOR drive
proper
assembly
movement.
removal" on
page 4-34.
2. "System
board
removal" on
page 4-90.
"System
4-90.