Troubleshooting By Image Fault; The Copy Is Too Light (Halftone Areas Only); The Copy Is Too Light (Dark Areas As Well); The Copy Is Too Light (Extremely Light Overall) - Canon PC400 Service Manual

C. Troubleshooting by Image Fault

1. The copy is too light (halftone areas only).

2. The copy is too light (dark areas as well).

3. The copy is too light (extremely light overall).

Cause
Lens, Reflecting plate,
Intensity sensor
Transfer charging
roller
Copy paper
Cartridge
DC controller/DC
power supply PCB
COPYRIGHT © 1998 CANON INC.
Step Checks
1 Clean the lens, reflecting plate,
and intensity sensor.
Is the problem corrected?
2 Press the Copy Start key, and
switch the copier OFF in the
middle of operation; then, open
the top cover.
Is the toner image on the pho-
tosensitive drum more or less
normal before transfer?
Be sure to check quickly to
protect the drum against light.
3 Is the transfer charging roller
normal?
4 Try paper fresh out of package.
Is the copy density higher?
5 Replace the cartridge.
Is the problem corrected?
CANON PC400/420/430,FC200/220 REV.0 JAN.1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 10 TROUBLESHOOTING
YES/NO Remedies
YES End.
NO Go to step 5.
NO 1. Re-attach the charging
roller.
2. Replace the charging
roller.
YES 1. The paper may be
moist; advise the user
on the correct method
of storage.
2. Advise the user that the
use of non-recom-
mended paper may not
bring about the best
results.
YES End.
NO Replace the DC controller/
DC power supply PCB.
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