Technical information

COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON CLC5000 REV.0 JAN. 2001
CHAPTER 5 TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
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3.4.10 The copy has white spots.
1) Is there a small lump of toner in the middle of a spot?
YES: Go to step 6.
Developing assembly
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.
NO: Check the developing assembly and the developing cylinder for
which the problem is noted; if a fault is found, clean or replace it.
Photosensitive drum, Transfer belt
3) • Check the photosensitive drum and the transfer belt for scratches.
• Check the transfer belt for scratches and deformation.
YES: Replace the photosensitive drum or the transfer drum belt.
Fixing roller
4) Is the problem noted at intervals of about 180 mm?
YES: Check the fixing roller for scratches and deformation.
Transfer current
5) Execute the following:
• Check to find out the present zone by referring to the absolute
value of the machine inside temperature (‘DISP>ANALOG’ in
service mode).
0 ~ 580 g: zone A
581 ~ 1800 g: zone B
1801g go or more: zone C
• Check to find out the type of paper used and whether single-sided
or double-sided is used.
• Select the following in service mode: ‘ADJUST>HV-TR’
• Decrease the setting value of the transfer current corresponding
to the conditions of occurrence (zone, paper type, single-sided/
double-sided) to ‘3’ for al colors.
• If the symptoms are not corrected, reduce the value by another ‘3’.
Waste toner (caking)
Developer (caking)
6) Check to find out whether the lump of toner is of waste toner or de-
veloper.
Is it of waste toner?
• Waste toner: gray (mixed colors)
• Developer: C, M, Y, or Bk
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.