Canon LBP1760P, Service Manual

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I-5. Dots in vertical line
<Possible causes>
1. Dirty static charge eliminator
Action: Clean the eliminator with brush.
2. Poor contact between the engine controller PCB static charge eliminator contact and the
eliminator
Action: Clean the contacts if dirty. If the problem still remains after cleaning, or parts are
deformed or damaged, replace them.
3. Deformation or deterioration of the transfer charging roller
Action: Replace the transfer charging roller.
4. Poor contact between the engine controller PCB transfer charging roller and its shaft
Action: Clean the contacts if dirty. If the problem still remains after cleaning, or parts are
deformed or damaged, replace them.
5. Defective engine controller PCB
Action: Replace the engine controller PCB.
I-6. Dirt on back of paper
<Possible causes>
1 Dirty paper
Action: Replace the paper to new one. At the same time, instruct the appropriate way to
store paper to the user.
2. Periodic dirt (cassette feed roller, feed roller, pre-transfer roller, transfer charging roller, pres-
sure roller)
Action: Identify and clean the dirty roller according to Table 4-2-1 on page 4-??. If dirt can-
not be removed, replace the dirty roller.
3. Dirty feed belt, feed guide or fixing unit entrance guide
Action: Clean the dirty areas.
I-7. Vertical lines
<Possible causes>
1. Circumferential scars on the photosensitive drum
Action: Replace the cartridge.
2. Dirty fixing unit entrance guide
Action: Clean the guide.
3. Scar(s) on fixing film unit
Action: Remove the cause of the scar(s) and replace the unit.
I-8. Black horizontal lines
<Possible causes>
1. Horizontal scar(s) on the photosensitive drum
Action: Replace the cartridge.
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CHAPTER 4