Canon CP660 Service Manual page 306

CHAPTER 10 TROUBLESHOOTING
11 The print has white spots.
Cause Step
Toner cartridge 1
Photosensitive 2
drum unit
Secondary 3
transfer belt
assembly
Intermediate 4
transfer drum
unit
Secondary 5
transfer belt
assembly
High-voltage 6
PCB 2 (inade-
quate transfer
bias output)
DC controller 7
PCB
Note:
See Table 10-202.
12 The print has poor fixing.
Cause Step
Fixing assem- 1
bly
2
DC controller 3
PCB
Note:
See Table 10-202.
10-24
COPYRIGHT © 1999 CANON INC.
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Checks
Does any of the developing cylin-
ders of the toner cartridge have a
fault?
Does the photosensitive drum or the
primary charging roller have a fault?
Does the unlocking mechanism of
the secondary transfer belt assem-
bly have a fault?
Is the intermediate transfer drum
unit deformed or is soiled with oil?
Is the contact of the secondary
transfer belt assembly (for sec-
ondary transfer bias) or the contact
for secondary transfer bias of the
printer unit soiled?
Replace the high-voltage PCB 2. Is
the problem corrected?
Checks
Is the upper/lower fixing roller
scratched or deformed?
Is the upper/lower fixing thermistor
soiled?
Yes/No
YES
YES
YES
YES
YES
YES
YES
Yes/No
YES
YES
NO
CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
Replace the problem
cartridge.
Replace the photosen-
sitive drum cartridge.
Replace the problem
part.
Replace the intermedi-
ate transfer drum unit.
Clean the contact. If it
is deformed or dam-
aged, replace the prob-
lem part. Also, check
for a displaced contact.
Replace the high-volt-
age PCB 2.
Replace the DC con-
troller PCB.
Action
Replace the
upper/lower fixing roller
or the fixing assembly.
Clean the upper/lower
fixing thermistor.
Replace the DC con-
troller PCB.