Canon LBP-2000 Service Manual page 165

CHAPTER 4
2 - 1 0 . White spots
<Possible Causes>
1 . The cartridge is running out of toner.
Action: Remove the cartridge from the Printer, and shake it as instructed in Chapter 1; then,
fit it back into the machine. If the problem is not corrected, replace the cartridge.
2 . The transfer charging roller is soiled or deformed.
Action: Replace the transfer charging roller.
3 . The contact of the toner level sensor 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.
4 . The photosensitive drum, developing cylinder, or toner level sensor is faulty.
Action: Replace the cartridge.
5 . The DC controller PCB is faulty.
Action: Replace the DC controller PCB.
2 - 1 1 . White vertical lines
<Possible Causes>
1 . The cartridge is running out of toner.
Action: Remove the cartridge from the Printer, and shake it as instructed in Chapter 1; then,
fit it back into the Printer. If the problem is not corrected, replace the cartridge.
2 . There is a scratch in the peripheral direction of the photosensitive drum.
Action: Replace the cartridge.
3 . The developing cylinder is faulty.
Action: Remove the cause of the scratch, and replace the cartridge.
4 . The laser outlet of the Printer or the laser inlet of the cartridge is coated with foreign matter.
Action: Remove the foreign matter.
5 . There is a scratch on the fixing roller.
Action: Remove the cause of the scratch, and replace the fixing assembly.
6 . The mirror inside the laser/scanner unit is soiled.
Action: Replace the laser/scanner unit.
2 - 1 2 . White horizontal lines
<Possible Causes>
1 . There is a horizontal scratch across the photosensitive drum.
Action: Replace the cartridge.
2 . There is a scratch on the fixing roller.
Action: Remove the cause of the scratch, and replace the fixing assembly.
4 - 14