Canon LBP-1210 Service Manual page 170

CHAPTER 4
Action: Replace the laser/scanner unit.
8) Defective engine controller PCB
Action: Replace the engine controller PCB.
9) Defective interfece controller PCB
Action: Replace the interfece controller PCB.
II-2. Dark
<Possible causes>
1) The image density is improperly adjusted.
Action: Adjust the image density by operating the external device.
2) Poor contact in the drum grounding contact on the engine controller PCB and the cartridge
contact.
Action: Clean the contacts if dirty. If the problem still remains after cleaning, or parts are
deformed or damaged, replace any defective parts.
3) Poor contact in the primary charging bias contact on the engine controller PCB and the car-
tridge contact.
Action: Clean the contacts if dirty. If the problem still remains after cleaning, or parts are
deformed or damaged, replace any defective parts.
4) The laser/scanner unit is defective.
Action: Replace the laser/scanner unit.
5) The engine controller PCB is defective.
Action: Replace the engine controller PCB.
6) Defective interfece controller PCB
Action: Replace the interfece controller PCB.
II-3. Completely blank
<Possible causes>
1) The laser shutter open/close projection of the cartridge cover is damaged.
Action:Replace the cartridge.
2) The laser shutter arm or laser shutter is defective or damaged.
Action: Check the laser shutter arm and laser shutter. If they do not move smoothly, or
parts are damaged, replace any defective parts.
3) Poor contact in the developing bias contact on the engine controller PCB and the cartridge
contact.
Action: Clean the contacts if dirty. If the problem still remains after cleaning, or parts are
deformed or damaged, replace any defective parts.
4) The engine controller PCB is defective.
Action: Replace the engine controller PCB.
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