Canon CLC 1120 Service Manual page 606

8 The copy has white spots (horizontal).
Cause
Mirror base rail,
original exposure
system cable
Developing
assembly
Primary charging
assembly, transfer
charging
assembly
Copy paper
Photosensitive
drum
Transfer charging
assembly
Transfer drum
sheet
Attraction
Transfer drum
fixing roller
COPYRIGHT © 1999 CANON INC.
Step
1 Generate a halftone test print
(TYPE=5). Is the problem noted?
2 Is the problem noted in a specific
color only?
3 Is the problem noted at the same
position on copies made in
continuous mode, but at different
positions on copies made at
intervals?
4 Is the copy paper moist? Try copy
paper fresh out of package. Is the
problem corrected?
5 Is there a fault in the flange or the
drive gear of the photosensitive
drum?
6 Clean the transfer blade with a
blower brush. Is the problem
corrected?
Is the transfer blade or the transfer
blade protective sheet warped or
bent?
7 Are there scratches or dents in the
transfer drum sheet?
8 Is copy paper in even contact with
the transfer drum sheet? Make a
check using
FUNCTION>ATTRACT>ATT-
ON in service mode.
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 13 TROUBLESHOOTING
Checks Yes/No Action
NO · Clean the rail of the
mirror base.
· Check the cable of the
original scanning
system.
YES Check the developing
cylinder of the color for
which the problem is
noted.
NO 1. Check the primary
charging assembly
and the transfer
charging assembly
for leakage.
2. Go to step 7.
YES Replace the paper.
Advise the user on the
correct method of
storage.
YES Replace the
photosensitive drum.
YES End.
YES Replace the transfer
charging assembly.
YES Replace the transfer
drum sheet.
· If scratches are found,
be sure to find out its
cause.
NO See 48. "Attraction
fails."
YES · Check the transfer
drum for wobbling.
· Check the fixing roller
(upper, lower) for
deformation.
13-79