Canon CLC5000 - Checking the High Voltage Control System

COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON CLC5000 REV.0 JAN. 2001
CHAPTER 5 TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
5-60
2.10.3 Checking the High Voltage Control System
a.Outline
If an image fault occurs, you must first determine whether the cause is the latent static for-
mation block which includes the photosensitive drum and the potential control system or the
developing/transfer system.
The CLC5000’s high-voltage is controlled to a specific level using the environment sensor
and the potential sensor.
b.Target Contrast Potential
The primary grid bias or the developing bias control mechanism may be checked by can-
celing the auto setting mechanism by the environment sensor for target contrast potential.
1) Select ‘VCONT’ of ‘ADJ-MISC’ under ‘ADJUST’ in service mode.
2) Select an appropriate value from the target contrast voltage levels in the following table,
and enter it.
CMYK
0 Auto Auto Auto Auto
1 370.00 365.00 390.00 420.00
2 370.00 365.00 390.00 420.00
3 370.00 365.00 390.00 420.00
4 355.00 345.00 370.00 410.00
5 335.00 325.00 340.00 390.00
6 315.00 295.00 310.00 380.00
7 290.00 275.00 295.00 370.00
8 225.00 225.00 245.00 330.00
3) Execute ‘FUNC > EPC’ in service mode.
4) Make copies, and check the images.
• If the image is better, suspect a fault in the environment sensor or the environment mea-
surement PCB.
5) Return the setting of ‘VONT’ of ‘ADJ-MISC’ under ‘ADJUST’ in service mode to ‘0’.
Sensor Environment sensor
Environment Primary grid bias
sensor Transfer blade bias
Separation charging bias
Potential sensor Primary grid bias
Developing bias