Canon NP6412 Service Manual page 346

CHAPTER 11 TROUBLESHOOTING
12 The copy has white spots. (horizontal)
Cause Step
Copy paper 1
2
Scanner rail 3
Scanning
lamp, Devel-
oping bias
13 The back of the copy is soiled.
Cause Step
------------ 1
Transfer 2
guide assem-
bly
Feeding 3
assembly
Pickup guide
assembly,
Delivery
roller
11-60
COPYRIGHT © 1999 CANON INC.
Checks
Is the paper of a recommended type?
Try paper fresh out of package. Is the
problem corrected?
Is the problem noted at the same
position on all copies?
Checks
Turn off the power while copy paper is
moving through the feeding assembly.
Is the back of the paper soiled?
Is the transfer guide assembly soiled?
Is the feeding assembly soiled?
CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
YES/NO Action
YES Try a recommend
type. If the results are
good, ask the user to
use a recommended
type.
YES The paper may be
moist. Instruct the user
on the correct method
of storing paper.
YES 1. Check the scanner
rail for foreign
matter.
2. Adjust the tension
of the scanner cable.
NO Check the scanning
lamp for flickering
and the presence/
absence of a develop-
ing bias.
YES/NO Action
NO Go to step 3.
YES 1. Clean the transfer
guide.
2. Clean the registra-
tion roller.
3. Check the varistor.
4. Check the develop-
ing assembly for
leakage of toner.
YES Clean the feeding
assembly.
NO Clean the pickup guide
assembly and the
delivery roller.