The Scanning Lamp Fails To Turn On - Canon NP6512 Service Manual

CHAPTER 11 TROUBLESHOOTING
20 The blanking lamp fails to turn on.
Cause Step
Side blank- 1
ing PCB
DC control-
ler PCB
21 The pre-exposure lamp fails to turn on.
Cause Step
Pre-exposure 1
lamp PCB
DC control-
ler PCB

22 The scanning lamp fails to turn on.

Cause Step
Scanning 1
lamp
Fuse (FU1) 2
Lamp 3
DC control- 4
ler PCB
Composite
power
supply PCB
11-74
COPYRIGHT © 1999 CANON INC.
Checks
Remove J106 from the DC control
PCB, and set the meter range to 1 k ;
then, connect the meter probes to
J106-1 and -2 on the harness side. Is
the meter reading about 20 ?
Checks
Remove J121 from the DC control
PCB, and set the meter range to 1 k ;
then, connect the meter probes to
J121-1 and -2 on the harness side. Is
the meter reading about 4 ?
Checks
Turn off the power switch, and discon-
nect the power plug from the power
outlet.
Is the scanning lamp (LA1) mounted
correctly?
Set the meter range to 1 k , and
connect the meter probes to both
terminals of the fuse (FU1). Does the
index of the meter swing?
Disconnect the connector J910 from th
ecomposite power supply PCB, and set
the tester range to 1k .
Does the tester index swing when the
probes are connected to J910-1 and
J910-3 on the lamp side?
Replace the DC controller PCB. Is the
problem corrected?
CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
YES/NO Action
NO Check the harness; if
normal, replace the
side blanking PCB.
YES Replace the DC
controller PCB.
YES/NO Action
NO Check the harness; if
normal, replace the
pre-exposure lamp
PCB.
YES Replace the DC
controller PCB.
YES/NO Action
NO Mount the scanning
lamp correctly.
NO Replace the fuse
(FU1).
NO Check the cable from
the composite power
supply PCB to the
lamp; if normal,
replace the lamp.
YES End.
NO Check the wiring
between the DC
controller PCB and the
composite power
supply PCB; if nor-
mal, replace the
composite power
supply PCB.