Canon LBP-1760 Service Manual page 193

Action: Replace the engine controller PCB.
M-27. "LOAD <SIZE> IN ENV." message appears when the specified sized envelope is in
the envelope feeder.
<Possible causes>
1. Damaged envelope detection lever
Action: Replace the lever.
2. Defective envelope feeder driver PCB
Action: Replace the envelope feeder driver PCB.
3. Defective engine controller PCB
Action: Replace the engine controller PCB.
M-28. "CLOSE FACE-UP TRAY" message appears when the face-up tray is closed at the
time of using duplexing unit
<Possible causes>
1. Spring is out of position
Action: Remove the right cover of the duplexing unit and check the spring. If the spring is
out of position, set it in the correct position.
2. Damaged top cover sensor lever of the duplexing unit
Action: Replace the top cover.
3. Defective face-up tray paper sensor
Action: Replace the sensor.
4. Defective duplexing unit driver PCB
Action: Replace the duplexing unit driver PCB.
M-29. "PAPER JAM" message appears when the paper jam has not occurred, and the
printer cannot be in READY mode.
<Possible causes>
1. Top of page sensor lever does not move smoothly or is damaged.
Action: Set the lever to move smoothly. Replace it if damaged.
2. Fixing unit delivery sensor lever does not move smoothly or is damaged.
Action: Set the lever to move smoothly. Replace it if damaged.
3. Defective top of page sensor
Action: Replace the sensor.
4. Defective fixing unit delivery paper sensor 1
Action: Replace the sensor.
5. Defective engine controller PCB
Action: Replace the engine controller PCB.
CHAPTER 4
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