Canon LBP-1120 Service Manual page 90

CHAPTER 4
III-1. Paper Pickup Unit
<Possible Causes>
1. The paper top sensing lever does not move smoothly or is damaged.
Action: If the lever is not installed properly, reinstall it correctly. If the lever is damaged or deformed,
replace it.
2. Defective paper top sensing lever spring.
Action: If the spring is out of place, set it in the right position. If the spring is deformed or damaged,
replace it.
3. Worn, deformed or dirty pickup roller or feed roller
Action: Clean the rollers if dirty. If the rollers are worn or deformed, replace them.
4. Defective lifting plate spring
Action: If the spring is out of place, set it in the right position. If the spring is deformed or damaged,
replace it.
5. Poor contact in the connectors on the main motor drive signal line.
Action: Reconnect the connector J007F on the main motor.
6. Poor contact in the connectors on the pickup roller solenoid drive signal line.
Action: Reconnect the connector J204F on the engine controller PCB.
7. Defective pickup roller solenoid
Action: Disconnect the connector J204F on the engine controller PCB. Measure the resistance between
the connector J204-1 and J204-2 on the cable side. If the measured value is not about 120Ω,
replace the pickup roller solenoid.
8. Defective paper top sensor.
Action: Replace the paper top sensor.
9. Defective main motor.
Action: Replace the main motor.
10. Defective engine controller PCB.
Action: Replace the engine controller PCB.
III-2. Fixing and Delivery Unit
<Possible Causes>
1. Defective deflector.
Action: If the deflector is worn, broken, nicked or damaged, replace it.
2. Dirty or scarred fixing unit entrance guide or toner build-up on the guide.
Action: Clean the guide if dirty. Replace the guide if the dirt cannot be removed.
3. The pressure (nip width) of the pressure roller is not within the specification.
Action: Replace the fixing pressure units.
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