Canon NP6317 Service Manual page 194

CHAPTER 10 TROUBLESHOOTING
10. White strips (in paper feed direction)
11. Narrow white lines (in paper feed direction)
Cause/Problem
Procedure
area
Fixing assembly 1
Primary corona 2
assembly
Developing as- 3
sembly
Copy paper 4
Photosensitive 5
drum
Light from out-
side
Transfer corona 6
assembly
Static charge
eliminator
10-30
Check
Press the COPY START key with the
copyboard cover open, then switch the copier
OFF to stop the copy paper on the feeder. Are
there any white strips or narrow white lines on
the copy image before the paper passes through
the fixing assembly?
Does the image improve after the corona wires,
grid plate and frame of the primary corona as-
sembly are cleaned?
Is the surface of the developing cylinder coated
uniformly with toner?
Does the image improve when fresh copy paper
is used?
Are there any scratches around the circumfer-
ence of the photosensitive drum?
Does the image improve after the corona wires
and frame of the transfer corona assembly are
cleaned?
COPYRIGHT © 1999 CANON INC.
Result
No
Yes
No
Yes
Yes
No
Yes
No
CANON NP6317 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
1. Clean the upper and
lower inlet guides of the
fixing assembly.
2. Check the upper fixing
roller.
3. Check and clean the
separation claws and fix-
ing blade.
Wipe the corona wires with
dry lint-free paper; then,
clean them with alcohol. If
the dirt will not come off,
replace the corona wires.
1. If the trouble is in the
black developing assem-
bly, check the edge of the
blade. If there is no toner
in the developing assem-
bly, see the sub-section
"ADD TONER indicator
does not go ON."
2. If the trouble is in the CT
unit, try putting the CT
unit in the storage box
and shaking it vigor-
ously. If the image does
not improve, replace the
CT unit.
The paper may be absorb-
ing moisture, so instruct the
user about the correct
method of storing paper.
Replace the drum unit.
(Find out the causes of the
scratches on the drum.)
Check if outside light is
striking the photosensitive
drum.
End.
Clean the static charge
eliminator.