The Copy Has Black Lines (Vertical, Fine) - Canon NP6621 Service Handbook

IMAGE FAULTS
9

The copy has black lines (vertical, fine).

Cause Step
1
Transfer 2
guide
Photosensi- 3
tive drum
Exposure
system
Fixing 4
assembly
3–10
Checks
Press the Copy Start key, and turn
OFF the power switch while the copy
paper is in the feeding assembly. At
this time, does the copy image before
the fixing assembly have black lines?
Is the transfer guide soiled? (Check in
particular the upper transfer guide.)
Are there scratches or black lines
around the surface of the photosensi-
tive drum? Check if the lines, if any,
disappear when the surface of the
photosensitive drum is wiped with a
flannel cloth coated with toner.
Are there scratches or black lines
around the surface of the upper fixing
roller?
Yes/No Remedy
NO Go to step 3.
YES Clean the guide.
YES Replace the drum cartridge.
If there are scratches, find
out the cause.
NO Check the exposure system.
YES 1. Replace the upper fixing
roller.
2. Check and clean the
separation claws and
fixing blade.
NO Check the inlet of the fixing
assembly for dirt.