Canon LBP-1000 Service Manual page 131

II-8. Black horizontal lines
<Possible causes>
1. Horizontal scar(s) on photosensitive drum
Action: Replace the cartridge.
2. Dirty, deformed or worn fixing film unit
Action: Replace the fixing film unit.
II-9. Dirt
<Possible causes>
1. Dirty paper
Action: Replace the paper with new one. Advise the customer on how to store paper.
2. Periodic dirt (registration roller, fixing film unit, EP-32 cartridge)
Action: Identify and clean the dirty part(s) according to Table 4-2-1 on page 4-11. If the dirt
cannot be removed, replace the dirty part(s).
3. Dirty delivery roller
Action: Clean the delivery roller.
II-10. Blank spots
<Possible causes>
1. Lack of toner
Action: Remove the cartridge from the printer. Rock the cartridge in the way described in
the chapter 1, and then install it back in the printer. If the problem persists, replace
the cartridge.
2. Dirty or deformed transfer charging roller.
Action: Replace the transfer charging roller.
3. Defective photosensitive drum or developing cylinder
Action: Replace the cartridge.
II-11. White vertical lines
<Possible causes>
1. Lack of toner
Action: Remove the cartridge from the printer. Rock the cartridge in the way described in
the chapter 1, and then install it back in the printer. If the problem persists, replace
the cartridge.
2. Circumferential scars on the photosensitive drum
Action: Replace the cartridge.
3. Defective developing cylinder
Action: Replace the cartridge.
4. Foreign materials are deposited on the laser outlet of the printer or the laser inlet of the car-
tridge.
CHAPTER 4
4 - 11