Canon 1000 Service Manual page 514

7. TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
10 The copy has white spots.
Cause Step
Developing
assembly
Photosensitive
drum, Transfer
belt
Fixing roller
Waste toner
(caking)
Developer
(caking)
7-78
COPYRIGHT © 2001 CANON INC.
Checks
1 Is there a small lump of toner in the
middle of a spot?
2 Generate a halftone test print
(PGTYPE=5). Is the problem noted?
If all colors, go to step 4.
If a specific color, go to the next step.
3 • Check the photosensitive drum
and the transfer belt for scratches.
• Check the transfer belt for
scratches and deformation.
4 Is the problem noted at intervals of
about 180 mm?
5 Check to find out whether the lump of
toner is of waste toner or developer.
• Waste toner: gray (mixed colors)
• Developer: Y, M, C, or Bk
Yes/No
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
YES Go to step 5.
NO Check the developing
assembly and the devel-
oping cylinder for which
the problem is noted; if a
fault is found, clean or
replace it.
YES Replace the photosensi-
tive drum or the transfer
drum belt.
YES Check the fixing roller for
scratches and deforma-
tion.
YES Check the end seal of the
photosensitive drum
cleaner blade.
Check the end of the
cylinder of the developing
assembly for dirt.
NO • Replace the developer.
• Replace the developing
assembly.