Canon CLC 1120 Service Manual page 863

CHAPTER 13 TROUBLESHOOTING
Code
E020
13-336
COPYRIGHT © 1999 CANON INC.
Cause
The backup data on the CPU PCB is
faulty* or the initial settings have not
been made.
*Be sure to initialize the RAM of the
DC-CPU and enter the values
recorded on the service label.
The developer has deteriorated.
· The developing cylinder fails to
rotate.
· The developing assembly is not
locked.
· The toner concentration (patch
detection) sensor is faulty.
· The developer inside the
developing assembly is faulty.
· The toner level sensor is faulty.
· The concentration sensor is
subjected to stray light (no cover,
front cover open).
· The photosensitive drum has
deteriorated.
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Timing of detection
xx76 During copying sequence, the
level of D-M-TRGT/D-C-
TRGT/D-Y-TRGT (developer
target value) is '930' or more
because of an error in the
memory backup data.
xx80 When samplings are taken
during copying sequence, the
level of WINDOW-M/C/Y/K
(window soiling correction
coefficient) is '130' or more.
xx81 When samplings are taken
during copying sequence, the
level of WINDOW-M/C/Y/K
(window soiling correction
coefficient) is '70' or less.
xx90 When samplings are taken
during copying sequence, the
variation of SGNL-M/C/Y
levels is '102' or more.
xx91 When samplings are taken
during copying sequence, the
variation of REF-M/C/Y
levels is '102' or more.
xxA0 When samplings are taken
during copying sequence, the
level of SGNL-M/C/Y is '306'
or less.
xxA1 When samplings are taken
during copying sequence, the
level of REF-M/C/Y set
initially decreases (intensity)
by 30% or more.
xxA2 When samplings are taken
during copying sequence, the
level of PT-SIG-K is '51' or
less.
xxB0 When samplings are taken
during copying sequence, the
level of SGNL-M/C/Y is
'1020' or more (when feeding
10 sheets or more
continuously).
xxB1 When samplings are taken
during copying sequence, the
level of REF-M/C/Y set
initially increases (intensity)
by '30%' or more.