Canon NP6251 Service Manual page 640

41. The blanking exposure lamp fails to turn on.
Cause Step
DC controller
PCB
Blanking
exposure lamp
DC controller
PCB
42. The pre-exposure lamp fails to turn on.
Cause Step
DC controller
PCB
Pre-exposure
lamp PCB
COPYRIGHT © 1997 CANON INC.
Checks
1 Remove the blanking exposure
lamp, and connect the connector.
Select 'BLANK' in service mode
( ). Does the blanking
4
exposure lamp turn on when the
user mode key is pressed?
2 Replace the blanking exposure
lamp. Does the new lamp turn on
correctly?
Checks
1 Set the meter to the 30VDC
range. Does the voltage between
J103B-2 (–) and GND change
from 24 to 0 V when the Copy
Start key is pressed?
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
YES/NO Action
YES Check the wiring from
the blanking exposure
lamp to the DC controller
PCB; if normal, replace
the DC controller PCB.
YES End.
NO Check the wiring from
the blanking exposure
lamp to the DC controller
PCB; if normal, replace
the DC controller PCB.
YES/NO Action
NO Replace the DC
controller PCB.
YES Check the wiring from
the DC controller PCB to
the pre-exposure lamp
PCB; if normal, replace
the pre-exposure lamp.
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