Specifications

CHAPTER 11 TROUBLESHOOTING
COPYRIGHT © 1999 CANON INC. CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON) 11-58
4 The copy has uneven density. (darker at front)
5 The copy has uneven density. (lighter at front)
YES/NO
YES
YES
NO
Cause
Scanner
Toner
cartridge
Scanning
lamp
Transfer
charging
roller
Step
1
2
Checks
Clean the scanning lamp, reflecting
plate, lens, and mirror. Is the problem
corrected?
Turn off the power in the middle of a
copying run, and open the machine. Is
the toner image on the photosensitive
drum before transfer more or less
uneven?
Action
End.
1. Replace the toner
cartridge.
2. Replace the scan-
ning lamp.
1. Mount the transfer
charging roller
correctly.
2. Replace the transfer
charging roller
correctly.
6 The copy is foggy. (entire face)
YES/NO
NO
YES
NO
YES
Cause
------------
Scanner
Grounding
spring
Scanning
lamp, Devel-
oping bias
Step
1
2
3
Checks
Is the density correction dial (VR107)
or the density adjusting lever set to the
middle setting?
Clean the scanning lamp, reflecting
plate, lens, and mirror. Is the problem
corrected?
Set the drum unit in the machine. Is
there electrical continuity between the
PCB of the base of the drum and the
machine's top unit?
Action
Set the dial or the
lever to the middle
setting, and make a
copy. If the image is
still foggy, to step 2).
End.
Check to see if the
grounding spring is
mounted correctly (in
reference to the drum
drive gear).
1. Check the activation
of the scanning
lamp.
2. Check the develop-
ing assembly.