Canon NP6320 Service Manual page 210

CHAPTER 10 TROUBLESHOOTING
10. White strips (in paper feed direction)
11. Narrow white lines (in paper feed direction)
Step
Cause
Fixing assem- 1
bly
Primary co- 2
rona assembly
Developing 3
assembly
Copy paper 4
Photosensitive 5
drum
Light from
outside
Transfer co- 6
rona assembly
Static charge
eliminator
10-32
COPYRIGHT © 1999 CANON INC.
Checks
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 nar-
row white lines on the copy image before
the paper passes through the fixing assem-
bly?
Does the image improve after the corona
wires, grid plate and frame of the primary
corona assembly 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 circum-
ference of the photosensitive drum?
Does the image improve after the corona
wires and frame of the transfer corona as-
sembly are cleaned?
CANON NP6320 REV.0 DEC. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
YES/
Action
NO
NO 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.
YES Wipe the corona wires
with dry lint-free paper;
then, clean them with al-
cohol. If the dirt will not
come off, replace the co-
rona wires.
NO If the trouble is in the
black developing assem-
bly, check the edge of
the blade. If there is no
toner in the developing
assembly, see the sub-
section "Add Toner indi-
cator does not go ON."
YES The paper may be ab-
sorbing moisture, so in-
struct the user about the
correct method of storing
paper.
YES Replace the drum unit.
(Find out the cause of
the scratches on the
drum.)
NO Check if outside light is
striking the photosensi-
tive drum.
YES End.
NO Clean the static charge
eliminator.