Chapter 5 Troubleshooting
Rev. A

5-11

5.3.1 Unit Repair - C200 Main Board
This section describes the problems related to the mai n controller board(C200 main). The table bel ow
provides various symptoms, li kely causes, and checkpoints. The check points refer to wav eforms,
resistance, and other values to be checked to eval uate the operation of each component.
Symptom Condition Cause Checkpoint Solution
The printer
does not
operate at all.
CPU does
not operate. The reset
circuit does not
operate.
Check the waveform of
the +5V and /Reset signal
(IC8=5,1-pin/IC9=7,6-pin)
Replace IC8 or
IC9.
Control ROM
is not selected
correctly or it’s
dead.
If you can not find the
waveform at 2-pin of IC3,
the IC1 is dead, and if
you
can not find it at 20-pin of
IC3, the IC3 is dead.
Replace IC1 or
IC3.
RAM is not
selected
correctly or it’s
dead.
If you can not find the
waveform at 29,14-pin of
IC4, the IC1 is dead, and
if you can not find it at
28-pin of IC4, the IC4 is
dead.
Replace IC1 or
IC 4.
CRU2 is dead. Check the waveform at
27,28-pin of IC1. Replace the
CRU2.
The carriage
does not
operate
normally.
Carriage
motor does
not operate
at all.
IC2 is dead. Check the waveform at
72,73 and 75,76 pin of
IC14.
Replace IC2.
IC14 is dead. Check the waveform at
6-9 pin if IC14. Repl ace IC14.