Unit Repair - C200 Main Board - Epson 440 Service Manual

5.3.1

Unit Repair - C200 Main Board

This section describes the problems related to the main controller board(C200 main). The table below
provides various symptoms, likely causes, and checkpoints. The check points refer to waveforms,
resistance, and other values to be checked to evaluate the operation of each component.
Symptom
The printer CPU does
does not not operate.
operate at all.
The carriage Carriage
does not motor does
operate not operate
normally. at all.
Rev. A
Condition Cause
The reset
circuit does not
operate.
Control
is not selected
correctly or it's
dead.
RAM is not
selected
correctly or it's
dead.
CRU2 is dead.
IC2 is dead.
IC14 is dead.
Checkpoint
Check the waveform of
the +5V and /Reset signal
(IC8=5,1-pin/IC9=7,6-pin)
ROM 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.
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.
Check the waveform at
27,28-pin of IC1.
Check the waveform at
72,73 and 75,76 pin of
IC14.
Check the waveform at
6-9 pin if IC14.
Chapter 5 Troubleshooting
Solution
Replace IC8 or
IC9.
Replace IC1 or
IC3.
Replace IC1 or
IC 4.
Replace the
CRU2.
Replace IC2.
Replace IC14.
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