Canon GP160DF Service Manual page 255

4 Solid black
Cause Steps
Scanning lamp
Cartridge (pri-
mary charging
roller bias fault)
Cartridge
High-voltage
contact point of
the DC con-
troller PCB
CCD unit
Image proces-
sor PCB
5 Polka dots
Cause Steps
Cartridge (pho-
tosensitive
drum)
Transfer charg-
ing roller
Static charge
eliminator
Re-charging
eliminator
DC controller
PCB
COPYRIGHT © 1999 CANON INC.
Checks
1 Is the scanning lamp lit while copy-
ing?
2 Is there dirt on the contact point that
supplies high-voltage to the car-
tridge?
3 Is the trouble resolved when the car-
tridge is replaced?
4 Are problems occurring due to defor-
mity of the high-voltage contact point
pin JH401 on the DC controller
PCB?
5 Is the trouble resolved when the
CCD unit is replaced?
Checks
1 Is the surface of the photosensitive
drum scratched?
2 Is the transfer charging roller dirty?
3 Is the static charge eliminator dirty?
4 Is the re-charging eliminator dirty?
5 Are problems occurring due to defor-
mity of the high-voltage contact point
pin JH401 on the DC controller PCB?
CANON GP160 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 13 TROUBLESHOOTING
Yes/No Action
NO See the "Scanning lamp
does not light" section.
YES Clean the contact
point.
YES End
YES Repair it. When this is
not possible, replace
the DC controller PCB.
YES End
NO Replace the image
processor PCB.
Yes/No Action
YES Replace the cartridge.
YES Clean the roller. If it is
scratched, replace it.
YES Clean the static charge
eliminator.
YES Clean the re-charging
eliminator.
YES Repair it.
NO Replace the DC con-
troller PCB.
13-21