Canon 1130 Service Manual page 640

2 The copy has uneven density (vertical).
Cause
------------
------------
Moire
Scanner
Service mode
Developing
assembly
Grid plate
(primary charging
assembly)
Pre-exposure
lamp
COPYRIGHT © 2002 CANON INC.
Step Checks
1 Clean the primary charging
assembly, dust-proofing glass,
reflecting mirror, and lens. Is the
problem corrected?
2 Is the output of the halftone test
print (TYPE=5) normal for all
colors?
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 Clean the standard white plate,
scanning lamp, and reflecting plate.
Is the problem corrected?
5 Is the standard white plate or the
copyboard glass off its base?
6 Has the original scanning lamp
blackened?
7 Are the settings of 'CCD' in service
mode the same as those recorded
on the service label?
8 Execute FUNCTION>CCD>CCD-
ADJ. Is the problem corrected?
9 Is uneven density noted for all
colors?
10 Is the grid plate of the primary
charging wire normal?
11 Does the pre-exposure lamp turn
on during copying operation?
CANON CLC1100/1130/1150/1160/1180 REV.1 FEB. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 13 TROUBLESHOOTING
Yes/No
YES End.
NO Go to step 12.
YES Reduce the degree of
sharpness (photo), and
store the new setting as
part of standard mode.
· Keep in mind that too
low a setting will
reduce the contrast of
copies of photos.
YES End.
YES Mount the part properly.
YES Replace the part.
NO Enter the settings once
again.
NO Try replacing the image
processor PCB, analog
processor PCB, and the
like.
(After replacement,
execute the work under
II. C. 2.)
NO Check the developing
assembly and
developing cylinder for
which uneven density is
noted. If a fault is found,
clean or replace the part.
NO Correct the grid plate.
NO Check the connection of
J1008 on the DC driver
PCB and check the
wiring from J1008 to the
pre-exposure lamp PCB;
if normal, replace the
pre-exposure lamp PCB.
Action
13-69