Canon NP6317 Service Handbook page 41

9. Dark lines (thin lines in paper feed direction)
Cause/Problem
Procedure
area
1
Photosensitive 2
drum
Developing
system; Expo-
sure system
Fixing assem- 3
bly
Check
Press the COPY START key and switch
the copier OFF to stop the paper on the
feeder. Are there black lines on the copy
image before the paper passes through the
fixing assembly?
Are there any scratches or black lines
around the circumference of the photosen-
sitive drum? (In the case of black lines on
the drum surface, do the black lines on
copies disappear when the lines are gently
wiped off the drum surface with a piece of
flannel?)
Are there any scratches or black lines
around the circumference of the upper fix-
ing roller?
CHAPTER 4 IMAGE TROUBLESHOOTING
Result
No
Yes
No
Yes
No
Action
Check from step 3.
Replace the drum unit.
(If there are scratches,
find out what is causing
them before replacing
the drum unit.)
Check the developing
system and exposure
system.
1.Replace the upper fix-
ing roller.
2.Check and clean the
separation claws and
fixing blade.
Check for dirt at the inlet
of the fixing assembly.
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