Specifications

I
Table 5-4. Repair of a Problem in the BOARD ASSY., MAIN (Cont.)
Problem
Symptom
Cause Checkpoint
Solution
Self-test print-
ing is
abnormal.
Self-test is
not executed.
A particular
dot is not be-
ing printed.
The CPU can’t
measure the
voltage on
the
+35V
line.
IC4D is
defective.
IC2A is
defective.
Measure the voltage at Vref (pin 1) of
IC 1 C. The normal voltage is 4.741 V.
At
IC4D, check the input signal at pin 101
and the output signal at pin 46.
Adjust VR 1.
Replace
IC4D.
Replace IC2A.
‘a per is not
The paper
IC2A is
Replace
IC2A.
‘ed normally.
does not defective.
feed, or the
feed pitch is
abnormal.
‘rinting of da-
Data
corrup- IC4D or IC5D
Replace
IC4D
a from the
tion occurs is defective.
or
IC5D.
lost comput-
when the par-
}r is faulty. allel interface
is used.
5-16