Service manual

EPSON Stylus Color 400 Service Manual
Rev. A
5-11
5.3.1 Unit Repair - C206 MAIN Board
This section describes the problems related to the main controller board(C206 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.
Table 5-7. Repair of the C206 MAIN Board
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.
Replace IC14.