Canon GP335 Service Manual page 473

23 The copy has black or white dots after replacement of the drum.
Cause
Drum cartridge
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Step Check
1 Execute FUNCTION>DPC>D-
GAMAM in service mode, and
make a copy of the NA-3 Chart. Is
the copy image normal?
2 Set '1' to OPTION>BODY>PRIAC-
SW in service mode. Make a copy of
the NA-3 Chart. Is the copy image
normal?
CHAPTER 14 TROUBLESHOOTING
Yes/No
YES End.
YES End.
NO Replace the drum
cartridge.
Action
14-55