Lexmark C78x User Manual

2-80 Service Manual
5061
Step D
Black only retract (BOR) service check
Step Actions and questions Yes No
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?
Contact your next
level of support.
Go to step 2
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?
Repair or replace
parts as
necessary.
Go to step 3
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?
Go to step 4 Install the cable
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?
Go to step 5 Install correctly or
replace the flag if
damaged or
broken.
5
Check continuity of the paper level sensing cable.
Is there continuity?
Go to step 6 Replace the level
sensing cable.
6
Check the voltage at JTRAY1. It should measure
approximately +5 V dc.
Is the voltage correct?
Replace the level
sensing
assembly.
Replace the
system board.
See “System
board removal”
on page 4-90.
Step Actions and questions Yes No
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?
Go to “Print
quality service
check” on
page 2-95.
Go to step 2
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?
Replace in the
following order:
1. “BOR drive
assembly
removal” on
page 4-34.
2. “System
board
removal” on
page 4-90.
Determine which
component is
preventing the
proper
movement.

Lexmark C78x Specifications

General

Brand	Lexmark
Model	C78x
Category	Printer
Language	English