Canon CLC 1120 Service Handbook page 235

Code
The backup data on the CPU PCB is
E020
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.
Cause
CHAPTER 5 SELF DIAGNOSIS
Timing of detection
xx53 During copying sequence,
gain setting cannot be
performed because of an error
in the memory backup data
(the level of RGAN-P-M/C/Y/
K is '250' or more or '40' or
less).
xx60 During copying sequence, the
level of SGNL-M/C/Y set
initially is '777' or less
because of an error in the
memory backup data.
xx61 During copying sequence, the
level of REF-M/C/Y set
initially is '200' or less
because of an error in the
memory backup data.
xx62 During copying sequence, the
level of PT-REF-M/C/Y set
initially is '777' or less
because of an error in the
memory backup data.
xx63 During copying sequence, the
level of PT-SIG-M/C/Y is
'683' or less or that of PT-SIG-
K is '305' or less because of an
error in the memory backup
data.
xx64 During copying sequence, the
level of PT-REF-D is '400' or
less because of an error in the
memory backup data.
xx65 During copying sequence, the
level of PT-SIG-D is '400' or
less because of an error in the
memory backup data.
xx66 During copying sequence, the
level of D-M-TRGT/D-C-
TRGT/D-Y-TRGT (developer
target value) is '700' or less
because of an error in the
memory backup data.
xx70 During copying sequence, the
level of SGNL-M/C/Y set
initially is '859' or more
because of an error in the
memory backup data.
xx71 During copying sequence, the
level of REF-M/C/Y set
initially is '930' or more
because of an error in the
memory backup data.
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