Canon GP405 Service Manual page 469

19 The copy has horizontal fogging.
Cause
Scanning lamp
Drum cartridge
Wiring
Developing
assembly
Scanning system
Feeding system
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Step Check
1 Is the problem noted at the same
location on all copies made in
Direct?
2 Does the scanning lamp flicker
while moving forward?
3 Is the problem noted at intervals of
94 mm?
4 Is the wiring from the scanning
lamp to the composite power
supply PCB and to the power
supply normal?
5 Is the coating of toner on the
surface of the developing cylinder
normal?
6 Make a copy in Reduce. Is the
problem noted at a location
different from that on a copy made
is Direct?
CHAPTER 14 TROUBLESHOOTING
Yes/No
YES Go to step 5.
YES • If the scanning lamp
is blackened, replace
the lamp.
• Check the power
supply voltage.
YES Replace the drum
cartridge.
NO Correct the wiring.
NO Check the developing
bias.
YES Check the scanning
system.
NO Check the feeding
system.
Action
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