Dirt On Back; Vertical Lines; Horizontal Lines; Dirt On Front - Canon imageCLASS LBP6780dn Service Manual

5
Troubleshooting > Corrective Actions > Image Defects > Dirt on front

■ Dirt on back

F-5-6
The back of page is dirty
Cause
1) The print media is dirty
2) Dirt on leading edge of image (cassette pickup
roller)
3) Repetitive dirt (registration roller, transfer roller
or pressure roller)
4) The media feed belt, media feed guide or fixing
inlet guide is dirty

■ Vertical lines

Vertical line appears in image
Cause
1) Scratches on the circumference of the
photosensitive drum
2) The fixing inlet guide is dirty
3) Scratches on the fixing film
5 Troubleshooting > Corrective Actions > Image Defects > Dirt on front
Solution
Replace the print media to new one. Advice the
customer on how to store the print media.
Clean the cassette pickup roller. If the dirt does
not come off, replace the roller.
See "Repetitive image defects ruler" to identify
the dirty roller. Clean the dirty roller. If the dirt
does not come off, replace the roller.
Clean the dirty parts.
F-5-7
Solution
Replace the cartridge.
Clean the fixing inlet guide.
Replace the fixing unit.

■ Horizontal lines

F-5-8
Horizontal line appears in image
Cause
1) Horizontal scratches on the photosensitive
drum
2) The fixing film is dirty, deformed or worn

■ Dirt on front

T-5-6
F-5-9
The front of page is dirty.
Cause
1) The print media is dirty
2) Dirt on leading edge of image (Multi-purpose
tray pickup roller)
3) Repetitive dirt (Registration roller, fixing film
unit or cartridge)
4) The delivery roller is dirty
T-5-7
Solution
Replace the cartridge.
Replace the fixing unit.
Solution
Replace the print media to new one. Advice the
customer on how to store the print media.
Clean the Multi-purpose tray pickup roller. If the
dirt does not come off, replace the roller.
See "Repetitive image defects ruler" to identify
the dirty roller. Clean the dirty part. If the dirt does
not come off, replace the part.
Clean the delivery roller.
5-4
T-5-8
T-5-9
5-4