Canon CLC 1120 Service Manual page 635

CHAPTER 13 TROUBLESHOOTING
d. E020=xx90, xx91, xx92, xx93, xxA0, xxA1, xxA2, xxB0, xxB1, xxB2, xxC0, xxD0, xxE0
Cause
------------
Toner (uneven
concentration
inside developing
assembly)
Developer
------------
Stray light
Black toner
concentration
sensor
Toner
concentration
sensor
Photosensitive
drum
Developing
cylinder
Developing
assembly locking
assembly
Toner level sensor
13-108
COPYRIGHT © 1999 CANON INC.
Step Checks
1 Perform the instructions under
"E20 Making a Check" on the next
page. Is E020 still indicated?
2 Execute
COPIER>FUNCTION>INSTALL>
STIR-M/C/Y/I for the color for
which E020 is indicated. Is the
problem corrected?
3 Replace the developer for which
E020 is indicated, and execute
COPIER>FUNCTION>INSTALL>
INIT in service mode. Is the
problem corrected?
4 Is E020 indicated for Bk? (Is it
E020=04xx?)
5 Is the front cover open while the
transfer unit front cover is removed
(i.e., is the black toner
concentration sensor subject to
stray light)?
6 Replace the toner concentration
sensor of the color for which E020
is indicated. Is the problem
corrected?
7 Replace the photosensitive drum. Is
the problem corrected?
8 Is the developing cylinder of the
color for which E020 is indicated
rotating?
9 Is the locking of the developing
assembly of the color for which
E020 is indicated normal?
Yes/No
NO
YES
YES
NO
YES
NO
YES
YES
NO
NO
YES
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
End.
End.
End.
· Check the counter. If
the developers of other
colors are near the end
of life, replace the
developers of all
colors.
Go to step 6.
Mount the transfer unit
front cover (to shut out
the stray light).
Replace the black toner
concentration sensor.
End.
End.
Check the developing
cylinder drive system.
See "The developing
assembly fails to be
locked in position."
Check the level of toner
inside the hopper and the
toner lever sensor.