Canon CLC 1120 Service Manual page 598

3 The copy has uneven density (horizontal).
Cause
------------
------------
Moire
Photosensitive
drum, developing
assembly, fixing
roller
Service mode
(CCD)
Photosensitive
drum drive
system
Transfer/static
eliminating
system
Fixing unit
4 The copy has fogging.
Perform the Image Adjustment Basic Procedure.
COPYRIGHT © 1999 CANON INC.
Step
1 Clean the primary charging
assembly, dust-proofing glass,
reflecting mirror, lamp, and lens. Is
the problem corrected?
2 Is the uneven density noted in a
specific color of the output image
of the halftone test print
(TYPE=5)?
3 Is the uneven density caused by
moire patterns?
· A "moire" pattern refers to lines
of interference occurring when
making a copy of an original
consisting of dots.
4 Make an A3 copy. Is there a
difference in density between
leading edge and trailing edge?
5 Are the settings of 'CCD' in service
mode the same as those recorded
on the service label?
6 Execute FUNCTION>CCD>CCD-
ADJ. Is the problem corrected?
7 Is the problem noted at intervals of
several millimeters?
8 Is the transfer blade or the transfer
blade protective sheet warped or
faulty?
9 Are there scratches or dents in the
axial direction of the fixing roller
(upper, lower)?
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 13 TROUBLESHOOTING
Checks Yes/No Action
YES End.
NO Go to step 7.
YES Lower the degree of
sharpness (photo), and
store the new setting in
standard mode.
· Keep in mind that too
low a setting will
reduce the contrast of
copies of photos.
NO Check the
photosensitive drum,
developing assembly,
fixing roller.
NO Enter the settings once
again.
NO Try replacing the image
processor, analog
processor, and the like.
YES Check the drive system
of the photosensitive
drum.
YES Correct the warping of
the transfer blade. Or,
replace the transfer
charging assembly.
YES Replace the fixing roller.
NO Check the fixing oil
applying assembly, oil
hose, oil tank, oil pump,
and oil removing blade
for a fault, and replace
any faulty part.
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