The Copy Has A Blurred Image; The Copy Is Foggy - Canon NP7160 Service Manual

18. The copy has a blurred image.

Cause Step
Scanner cable
Scanner rail
Photosensitive drum
Developing gear
Drum drive system
19. The copy is foggy. (horizontally)
Step
Cause
Scanning lamp
(LA1), Lamp
regulator PCB
Developing roller
Developing bias
Scanner
Feeding assembly
COPYRIGHT © 1998 CANON INC.
Checks
1 Does the cable wind on the cable
pulley in layers while the scanner is
moving?
2 Move the No. 1 mirror mount slowly
by hand. Does it move smoothly?
3 Is the problem noted at intervals of
about 9.4 cm?
4 Is the problem noted at intervals of
about 3.2 cm?
Checks
1
Is the problem noted at the same
location on all copies made in Direct?
2
Does the scanning lamp flicker when
the scanner is moving forward?
3
Is the developing roller soiled with
toner, is the roller deformed, or is the
area in contact with the developing
roller (photosensitive drum) soiled
with toner?
4
Is the developing bias applied
correctly?
5
Make a copy in Reduce, and compare
it with a copy made in Direct. Is the
problem noted in a different location?
CANON NP7161/NP7160 REV.0 AUG. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 10 TROUBLESHOOTING
Yes/No
Actions
YES 1. Route the cable once again.
2. If the cable is twisted or frayed,
replace it.
NO Clean the surface of the scanner rail
with alcohol. Then, apply a small
amount of lubricant.
YES 1. Check the drum gear.
2. Check the end of the drum (in
contact with the developing roller)
for scratches and protrusions.
YES Check the developing assembly.
Check the drum drive system.
NO
Yes/No
Actions
Go to step 4.
YES
Check the scanning lamp and the
YES
lamp regulator PCB.
Clean or, if necessary, replace the
YES
developing roller.
Remove the developing assembly,
NO
and check the wiring; then, set it once
again.
Check the scanning system.
YES
Check the feeding assembly.
NO
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