Lexmark T652 Service Manual page 177

Step
3 Check the duplex guide assembly, front for damage.
Is the above component free from damage?
4 Check the sensor (duplex input) for proper operation.
1. Enter the diagnostic mode
2. Select Duplex tests
3. Select sensor test
4. Observe the line item "input"
Does the display on the operator panel, change every time
the sensing area of the above sensor is interrupted or
blocked.
5 Check the above sensor for proper connection.
Is the above sensor connected properly?
6 Check the aligner assembly for obstructions.
Is the above component free from obstructions?
7 Check the external duplex media path for obstructions.
Is the above component free from obstructions?
8
Check the external duplex unit assembly for proper
installation.
Is the above component properly installed?
9
Check the sensor (duplex input) for proper operation.
1. Enter the diagnostic mode
2. Select Duplex tests
3. Select sensor test
3. Observe the line item "input"
Does the display on the operator panel, change every time
the sensing area of the above sensor is interrupted or
blocked.
10 Perform a print test using the duplex.
Does the problem remain?
Check Yes
Go to step 4. Replace the
duplex guide
assembly, front.
Go to
guide assembly,
front removal
(T652, T654)" on
page
Go to step 6. Go to step 5.
Replace the Replace the
sensor (duplex connection.
input).
"Sensor
Go to
(duplex input)
removal (T652,
T654)" on
page 4-68.
Go to step 7. Remove
obstructions.
Go to step x Remove
obstructions.
Go to step 9. Remove then
properly re-install
the external
duplex unit
assembly.
Go to step 10. Replace the
external duplex
assembly.
Contact next Problem solved.
highest level of
tech support.
Diagnostic information
4062
No
"Duplex
4-21.
2-143