Canon GP215 Service Handbook page 43

3 The copy is too light. (overall, considerably)
Cause Step
1
2
Transfer
3
roller unit
4
High-voltage
5
cord,
Transfer
roller unit
High-voltage
transformer,
DC con-
troller PCB
Transfer
6
guide
Copy paper
Development
(fault)
Checks
Perform the Image Adjustment
Basic Procedure. Is the prob-
lem corrected?
Turn off the power switch in the
middle of copying, and open
the front door. Is the toner
image on the surface of the
photosensitive drum before
transfer more or less normal?
Is the transfer roller unit
installed securely?
Does leakage occur in the
transfer roller unit?
Is there electrical continuity
from the composite power sup-
ply PCB to the transfer roller
unit?
Set the feeding assembly in the
feeding position, and measure
the resistance between the
transfer guide and the mount
(metal portion) of the transfer
charging assembly rail with a
tester. Is the resistance 0 ?
Is the developing assembly in
firm contact with the photosen-
sitive drum? (Check if the
developing rolls are in firm con-
tact with the photosensitive
drum.)
TROUBLESHOOTING IMAGE PROBLEMS
Yes/No Action
YES End.
The image will become appre-
ciably light if the pattern print
is placed in reverse (left/right)
orientation. Be sure to place it
in correct orientation.
NO Go to step 9.
NO Install the transfer unit secure-
ly.
YES Check the transfer roller unit.
NO 1. Replace the high voltage
cord.
2. Check the transfer roller
unit.
YES Check the composite power
supply PCB and the DC con-
troller PCB.
YES Check to see if the transfer
guide should be in contact with
a metal portion (e.g., side plate
of the feeding assembly).
NO Try fresh copy paper or paper
of a different quality.
NO Re-install the developing
assembly.
YES 1. Check the developing
assembly.
2. Check the developing bias.
3–7