Canon LBP-2000 Service Manual page 161

2-2. Dark
<Possible Causes>
1. The image density setting is not correct.
Action: Operate the external device to adjust the image density.
2. The contact of the leaf spring for the drum ground and the contact of the cartridge are poor.
Action: If dirt is found, clean the contact. If the problem is not corrected after cleaning, or
deformation or damage is found, replace the faulty part.
3. The contact of the leaf spring for the primary bias and the contact of the cartridge are poor.
Action: If dirt is found, clean the contact. If the problem is not corrected, or deformation or
damage is found, replace the faulty part.
4. The contact for the primary bias on the DC controller PCB and the contact of the leaf spring for
the primary bias are poor.
Action: If dirt is found, clean the contact. If the problem is not corrected after cleaning, or
damage or wear is found, replace the faulty part.
5. The laser/scanner unit is faulty.
Action: Replace the laser/scanner unit.
6. The DC controller PCB is faulty.
Action: Replace the DC controller PCB.
2-3. Blank
<Possible Causes>
1. The protrusion for opening/closing the laser shutter of the cartridge is damaged.
Action: Replace the cartridge.
2. The laser shutter arm or the laser shutter has poor operation or is damaged.
Action: Check the movement. If not smooth, or damage is found, replace the faulty part.
3. The contact of the leaf spring for developing bias and the contact of the cartridge are faulty.
Action: If dirt is found, clean the contact. If the problem is not corrected after cleaning, or
deformation or damage is found, replace the faulty part.
4. The contact for the developing bias on the DC controller PCB and the contact of the left spring
for the developing bias are poor.
Action: If dirt is found, clean the contact. If the problem is not corrected after cleaning, or
deformation or damage is found, replace it with a faulty part.
5. The DC controller PCB is faulty.
Action: Replace the DC controller PCB.
CHAPTER 4
4 - 11