12. The copy has white spots (horizontal).
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
11-78
Cause
Developing
assembly
Drum
Copy paper
Scanner rail,
Scanner cable
Charging wire,
Photosensitive
drum
Checks
Is the problem noted at intervals
of about 52 mm?
Is the problem noted at intervals
of about 25 cm?
Try fresh copy paper. Is the
problem corrected?
Does the problem occur at the
same location on all copies?
Are there scratches on the surface
of the photosensitive drum?
Step
1
2
3
4
5
YES/NO
YES
YES
YES
YES
NO
YES
Action
1. Clean the developing
rolls.
2. Dry wipe the surface
of the developing
cylinder.
3. If the surface of the
developing cylinder
have scratches,
replace the
developing cylinder.
1. Clean the drum.
2. If scratches are found,
replace the drum.
The copy paper may be
moist. Advise the user
on the correct method of
sorting paper.
1. Check the scanner rail
for foreign matter.
2. Adjust the scanner
cable.
Clean the charging
assembly.
Replace the
photosensitive drum.