Canon NP6251 Service Manual page 574

3) Press the user mode key .
• Non-auto control mode starts.
4) Press the Reset key twice.
Caution:
When non-auto control mode is executed, all control (corona current, intensity,
developing bias) is set to default settings stored in ROM.
Using Non-Auto Control Mode
Use non-auto control mode to find out if a fault, if any, is on the input or the output
side of the microprocessor on the DC controller PCB.
c. Zero-Level Check
You may use a zero-level check to find out whether the surface potential control
circuit is good or not.
Reference:
In a zero-level check, a check is made to find out whether the microprocessor
identifies a 0V condition when the surface potential of the drum is 0 V.
Using a zero-level check, you can find out whether the microprocessor on the DC
controller PCB or the measuring unit is good or not.
A zero-level check may be either of the following:
Method 1 enables you to check the lever shift circuit on the DC controller, while
method 2 enables you to check the potential measurement circuit.
COPYRIGHT © 1997 CANON INC.
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CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
( : START)
( : START)
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