Canon GP405 Service Manual page 462

CHAPTER 14 TROUBLESHOOTING
9 The copy has black lines (vertical, fine).
Cause
Exposure system
Primary charging
assembly
Photosensitive
drum
Fixing assembly
14-44
Step Check
1 Generate a halftone test print in
service mode. Enter '5' to
COPIER>PG>TYPE. Does the
output image have black lines?
2 Clean the primary charging roller in
user mode. Is the problem
corrected?
3 Are there scratches in the
peripheral direction of the
photosensitive drum?
• Wipe the black lines on the
surface of the photosensitive
drum with a cloth coated with
toner. Can they be removed?
4 Are there scratches in the
peripheral direction of the fixing
roller?
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Yes/No Action
NO The exposure system
may be faulty. Clean it.
YES End.
NO Replace the drum unit.
• If scratches are noted,
be sure to investigate
the cause.
YES Replace the fixing roller.
NO Check the fixing
assembly inlet for dirt.