Canon LBP-3260 Service Manual page 169

II-2. Dark
<Possible causes>
1. The image density is not adjusted correctly.
Action: Adjust the image density by operating the external device.
2. The drum grounding contact of the high-voltage power supply is not making a good connec-
tion with the cartridge contact.
Action: If the contacts are dirty, clean them. If the problem continues after cleaning, or
parts are deformed or damaged, replace them.
3. The primary bias contact of the high-voltage power supply is not making a good connection
with the cartridge contact.
Action: If the contacts are dirty, clean them. If the problem continues after cleaning, or
parts are deformed or damaged, replace them.
4. The high-voltage power supply PCB is defective.
Action: Replace the high-voltage power supply PCB.
5. The DC controller PCB is defective.
Action: Replace the DC controller PCB.
II-3. Completely blank
<Possible causes>
1. The projection for opening and closing the laser shutter of the EP-72 cartridge is damaged.
Action: Replace the cartridge.
2. The laser shutter arm or laser shutter is malfunctioning or damaged.
Action: If the laser shutter arm or laser shutter does not move smoothly, or parts are dam-
aged, replace them.
3. The developing bias contact of the high-voltage power supply is not making a good connec-
tion with the cartridge contact.
Action: If the contacts are dirty, clean them. If the problem continues after cleaning, or
parts are deformed or damaged, replace them.
4. The high-voltage power supply PCB is defective.
Action: Replace the high-voltage power supply PCB.
5. The DC controller PCB is defective.
Action: Replace the DC controller PCB.
II-4. All black
<Possible causes>
1. The primary bias contact of the high-voltage power supply is not making a good connection
with the cartridge contact.
Action: If the contacts are dirty, clean them. If the problem continues after cleaning, or
parts are deformed or damaged, replace them.
2. Defective primary charging roller
CHAPTER 4
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