Making Checks On The Printer Side (2/2) - Canon iR8500 Service Manual

1.1.3 Making Checks on the Printer Side (2/2)

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COPYRIGHT© 2001 CANON INC. 2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
<Checking for Fogging>
Check PG6 (solid white).
NO
Is it foggy?
YES
Make the following selections in
service mode:
COPIER>DISPLAY>DPOT>VDM.
Check the potential
Is the reading
NO
control system; if
of 'VDM' between
normal, replace the
360 and 420?
photosensitive drum.
YES
Make the following selections in
service mode:
COPIER>DISPLAY>DPOT>VL1M
Check the following; if
faulty, replace it:
Is the reading
NO
1. Laser output
of 'VL1M' between
2. Potential control
50 and 90?
system
YES
Make the following selections in
service mode, and decrease the
setting:
ADJUST>DEVELOP>DE-OFST:
A lower setting makes the image
lighter.
F06-101-03
CHAPTER 6 TROUBLESHOOTING
<Checking the Halftone Density>
Check PG4 (halftone).
Comparing
with No. 6 through
YES
No. 7 (halftone) of the
End.
Test Chart, is the
density about the
same?
NO
Make the following selections in
service mode, and set it between 1
and 9:
ADJUST>DENS>DENS-ADJ.
A higher setting makes the
image darker.
6-5