Canon NP6251 Service Manual page 645

CHAPTER 11 TROUBLESHOOTING
48. The Add Toner indicator fails to turn on.
Cause Step
Toner sensor
(hopper
assembly),
DC controller
PCB
DC controller
PCB
49. The Add Toner indicator fails to turn off.
Cause Step
Toner
Toner sensor
(TS1)
DC controller
PCB/Control
panel
11-114
COPYRIGHT © 1997 CANON INC.
Checks
1 Is there toner in the hopper
assembly?
2 Select 'P002' in service mode
( ). Move the toner around
2
the toner sensor (TS1) to expose
the sensor. Does bit 10 on the
message display indicate '0' (toner
absent)?
3 Open the upper cover of the
developing assembly. Is the toner
level sensor blocked by toner?
Checks
1 Is there toner at the rear of the
hopper assembly?
2 Select 'P002' in service mode
( ). At this time, does bit 10
2
on the message display indicate
'0' (toner absent)?
YES/NO
YES
NO
YES
YES
YES/NO
NO
YES
NO
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
Go to step 3.
1. Replace the toner
sensor (TS1).
2. Replace the DC
controller PCB.
1. Replace the DC
controller PCB.
2. Replace the control
panel.
End.
Action
The level of toner inside
the hopper is not
enough. Supply toner.
Replace the toner
sensor (TS1) of the
hopper assembly.
1. Replace the DC
controller PCB.
2. Replace the control
panel.