MFC-8220
SERVICE MANUAL
6-37
I-6 Black and blurred vertical streaks
Possible cause Step Check Result Remedy
Dirt on the
scanner
window.
1
Is there any dirt on that? Yes
Clean the scanner window.
Dirt on the white
tape.
2
Is there any dirt on that? Yes
Clean the white tape.
Dirt on the CIS. 3
Is there any dirt on that? Yes Replace the CIS.
Corona wire
failure
4 Is the vertical block streak
about 10mm wide?
(Check if the wire cleaner is at
its home position.)
Yes Return the wire cleaner to its
home position.
Dirt in the paper
feed system
5 Is the paper tray or feed
system on the drum unit dirty
with toner?
Yes Clean the toner off.
Scratch on the
drum
6 Is the drum surface scratched? Yes Replace the drum unit.
Dirt on the
drum.
7 Is the drum surface dirty with
toner in streaks?
Yes Replace the drum unit.
Scratch on the
heat roller
8 Is the surface of the heat roller
scratched?
Yes Replace the fixing unit.
NOTE:
• If you print the same pattern (especially vertical streaks) continuously, electrostatic charge
performance of the drum will decrease temporarily and black vertical streaks may appear
on the paper.
• This problem may occur with noise
due to the corona wire being dirty. In that case, clean
the corona wire with the wire cleaner.
User Check
(1) Clean the corona wire in the drum unit.
(2) Check that the corona wire cleaner is at the home position.
(3) Check that the toner cartridge is not empty.
(4) The drum unit may be damaged. Install a new drum unit.
(5) The toner cartridge may be damaged. Install a new toner cartridge.