Checking The Surface Potential Control System - Canon imageRUNNER 7095 Service Manual

Chapter 14
4) Remove the 2 screws [1], and detach the
potential sensor support plate [2].
F-14-40
5) Put back the developing assembly and the
process unit.
6) Connect the connector [1] of the potential
sensor.
F-14-41
7) Fit the potential checker electrode (FY9-3041)
[2] to the potential sensor [1].
[2]
F-14-42
When fitting the checker electrode to the poten-
tial sensor, make sure that the magnet of the
checker electrode will not come into contact with
the potential sensor cover.
8) Connect the cable [1] of the potential sensor
checker electrode to the frame assembly
(GND) [2] of the machine.
Never bring the clip into contact with the sensor
cover. Be sure to fit it fully away from the sensor
window.
14-22
[1]
[2]
[1]
[1]
F-14-43
9) Fit the door switch actuator in the door switch
assembly.
10) Turn on the powor.
11) Execute the following service mode items:
COPIER > FUNCTION > DPC > OFST
12) Record the value of <OFST> on the service
sheet.
13) Turn off the main power switch.
14) Detach the potential sensor checker electrode.
15) Put back the potential sensor support plate.
16) Turn on the power.
14.7.8 Checking the Surface Potential
Control System
a. Outline
If image faults occur, it is important to find out
whether the cause is in the latent static image for-
mation block (including the photosensitive drum
and the potential control system) or it is in the de-
veloping/transfer system, requiring a check on
the surface potential. (You can check the surface
potential in service mode.)
b. Disabling the Auto Control Mechanisms
As a way of checking the mechanisms used for
corona current control, lamp intensity control, or
developing bias control, you may disable the auto
control mechanisms (hereafter, non-auto control
mode).
As a first-aid measure when a fault exists in the
auto control mechanism, you may use non-auto
control mode; keep in mind that all outputs in
non-auto control mode are fixed to standard val-
ues.
1. Procedure
1) Make the following selections in service mode,
and enter '0':
COPIER > OPTION > BODY > PO-CNT.
2) Press the Reset key twice.
In non-auto control mode, all settings used for
coronal current control, intensity control, devel-
oping bias control will be set to standard settings
stored in ROM.
[2]
[1]
0010-9332