Canon LBP-2000 Service Manual page 162

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 . B l a n k
<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
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