Canon imageRUNNER 5065 series Service Manual page 422

Chapter 14
Disable the potential control mechanism
by entering '0' for the following:
COPIER>OPTIONAL>BODY>PO-CNT.
1. short CP33 on the controller PCB and GND.
2. disconnect the connector used between DC
controller PCBs of the potential control PCB.
Make the following selections in service mode:
COPIER>DISPLAY>DPOT>DPOT-K
1. Disconnect the cable used to short the check pins
2. Connect the connector used between the DC
Check to make sure that the potential measurement
PCB is supplied with power, and check the potential
sensor using a checking electrode.
14-8
Start
NO
Is the image
better?
YES
Turn off the main power
turn on the main power
NO
Is the value between
replace the DC
0 and 30?
controller PCB.
YES
turn off the main power
on the DC controller PCB.
controller PCBs of the potential control PCB.
turn on the main power
Checking the Laser Output
A
Enable potential control: COPIER>
OPTION>BODY>PO-CNT=1.
Make the following selections in
service mode, and enter '1':
COPIER>FUNCTION>DPC>DPC.
Switch off and on the main power
switch.
Check the following indications:
for copier images:
COPIER>DISPLAY>DPOT>VL2M
for printer images:
COPIER>DISPLAY>DPOT>VL2M-P
Is the indication
Check the laser output.
Is the laser output a
Replace the laser unit.
<Checking the Primary Output>
Turn off the potential control mechanism
by entering '0' for the following:
COPIER>OPTION>BODY>PO-CNT.
Measure the voltage HVT_PRIMARY of
J102A-11 on the DC controller PCB while
copying is under way.
Make the following selections in service mode
(primary charging assembly current level):
COPIER>DISPLAY>HV-STS>PRIMARY.
Convert the value (in uA) indicated while printing
is under way into a control voltage using the
Potential Control Conversion Table.
Is the difference
between the measured PR-CNT
and 'PRIMARY' shown in service
mode +/-10%?
YES
Try replacing the
high-voltage transformer. Is
the problem corrected?
NO
Try replacing the photosensitive drum.
If the problem is not corrected, go to
'Checking the Laser Output'.
F-14-10
Forced execution
of potential control
YES
70 ± 15 V?
NO
NO
limit value?
YES
F-14-11
NO
replace the DC
controller PCB.
YES
End
B