Checking The High Voltage Control System - Canon 1000 Service Manual

14) Press the Reset key.
15) Turn off the power switch.
16) Connect J1 of the environment measurement
PCB.
17) Remove the environment measurement sen-
sor from the environment measurement PCB,
and insert the environment sensor.
18) Install all covers.
b. Checking the Environment Sensor
1) Check the environment PCB.
2) Turn on the power switch, and leave it on for 5
min.
3) Start service mode, and select 'DISPLAY'.
4) Check the temperature and humidity on the
ANALOG screen.
BODY °C ............ data A1
BODY % ............ data A2
5) Press the Reset key, and turn off the power
switch.
6) Remove the environment sensor from the en-
vironment measurement PCB, and insert the
environment sensor calibration tool (TKN-
0456) in its place.
7) Turn on the service switch, and leave it on for 5
min.
8) Start service mode, and select 'DISPLAY'.
9) Check the temperature and humidity on the
ANALOG screen.
(data B)
BODY °C ............ data B1
BODY % ............ data B2
10) Compare data A and data B
• The difference between data A1 and data
B1 is 0 ±5.
• The difference between data A and data B is
0 ±20.
If the difference is outside the specification, re-
place the environment sensor.
11) Press the Reset key, and turn off the power
switch.
12) Remove the environment sensor calibration
tool from the environment measurement PCB,
and insert the environment sensor.
13) Install all covers.
The environment sensor calibration
tool (TKN-0456) is adjusted with high
precision at the factory. Keep it in a
sealed case with a drying agent.
COPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
7. TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
3 Checking the High Voltage
Control System
a. Outline
If an image fault occurs, you must first deter-
mine whether the cause is the latent static forma-
tion block which includes the photosensitive drum
and the potential control system or the developing/
transfer system.
The CLC1000's high-voltage is controlled to a
specific level using the environment sensor and
the potential sensor.
Sensor
Environment
sensor
Potential sensor
b. Target Contrast Potential
The primary grid bias or the developing bias
control mechanism may be checked by canceling
the auto setting mechanism by the environment
sensor for target contrast potential.
1) Select 'VCONT' of 'ADJ-MISC' under 'AD-
JUST' in service mode.
2) Select an appropriate value from the target
contrast voltage levels in the following table,
and enter it.
Environment sensor
Primary grid bias
Transfer blade bias
Separation charging bias
Primary grid bias
Developing bias
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