Canon CP660 Service Manual page 299

2 The print is too dark.
Cause Step
Density sensor 1
Grounding wire 2
contact (drum
cartridge)
Contact (drum 3
cartridge; for
primary charg-
ing bias)
High-voltage 4
PCB 1 (primary
charging bias
output)
3 The print is blank.
Cause Step
Laser shutter 1
2
High-voltage 3
PCB 1
High-voltage 4
PCB 1 (no
color/black
developing bias
output)
COPYRIGHT © 1999 CANON INC.
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Checks
Is the lens of the density sensor
soiled?
Is the contact of the grounding wire
of the drum cartridge or the contact
of the drum grounding wire for the
printer unit soiled?
Is the contact of the drum cartridge
(for primary charging bias) or the
contact for primary charging of the
printer unit soiled?
Replace the high-voltage PCB 1. Is
the problem corrected?
Checks
Is the boss for opening/closing the
laser shutter on the front cover or
the right cover of the printer unit
damaged?
Does the laser shutter arm and the
laser shutter move smoothly?
Are the connectors J5001 and J226
on the high-voltage PCB 1 connect-
ed securely?
Replace the high-voltage PCB 1. Is
the problem corrected?
CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 10 TROUBLESHOOTING
Yes/No Action
YES Clean the lens with a
special brush.
YES Clean the contact. If it
is deformed or dam-
aged, replace the prob-
lem part. Also, check
for a displaced contact.
YES Clean the contact. If it
is deformed or dam-
aged, replace the prob-
lem part. Also, check
for a displaced contact.
YES End.
NO Replace the DC con-
troller PCB.
Yes/No Action
YES Replace the front cover
or the right cover.
NO Replace the problem
part.
NO Connect them securely.
YES Replace the high-volt-
age PCB 1.
10-17