Canon GP405 Service Manual page 461

7 The copy is foggy (vertically).
8 The copy has black lines (vertical, fuzzy, thick).
Cause
Primary charging
roller
Scanner
Developing
assembly
Photosensitive
drum
External light
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Step Check
1 Clean the charging roller in user
mode. Is the problem corrected?
2 Clean the mirror, lens, and dust-
proofing glass. Is the problem
corrected?
3 Is the surface of the developing
assembly coated with an even layer
of toner?
4 Are there scratches in the
peripheral direction of the surface
of the photosensitive drum?
CHAPTER 14 TROUBLESHOOTING
Yes/No
YES End.
YES End.
NO 1.Check the edge of the
blade of the
developing assembly.
2.Dry wipe the surface
of the developing
cylinder.
YES Replace the drum unit.
NO Check the photosensitive
drum to make sure it is
not subjected to external
light.
Action
14-43