Canon NP6251 Service Manual page 622

11. E020
Cause Step
Hopper
assembly
sensor
Hopper
Connection
(between
hopper
assembly and
developing
assembly)
Toner sensor
DC controller
PCB
Connector
(hopper
assembly)
Outlet
(hopper
assembly)
COPYRIGHT © 1997 CANON INC.
Checks
1 Remove the upper cover of the
developing assembly. Is the devel-
oping assembly almost overflow-
ing with toner? (After the check,
be sure to install the upper cover.)
2 Is the hopper full of toner?
3 Select 'P002' in service mode
( ). Is bit 10 (TEP) of the
2
message display '0' (toner
absent)?
4 Set 'HPPR_MTR' in service mode
( ), and press the * key. At
4
this time, does the hopper motor
rotate for about 3 sec?
5 Install the developing assembly,
and set the copy count to '20'.
Select 'P002' in service mode (
). Does bit 9 (DTEP) on the
2
message display indicate '0' (toner
present) during copying?
6 Is the connector disconnected?
7 Is the end of the outlet cover bent,
limiting the amount of toner
moving from the hopper to the
developing assembly?
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
YES/NO Action
YES Go to step 6.
NO Go to step 5.
YES Replace the hopper
assembly sensor.
NO See "The hopper motor
fails to operate."
YES Check to make sure that
the hopper assembly
and the developing
assembly are connected
securely.
NO Replace the toner level
detection PCB.
YES Replace the DC
controller PCB.
YES Connect the connector.
YES Replace the seal of the
outlet, and replace the
hopper collars 1 and 2.
11-91