Epson FX-980 Service Manual page 55

FX-980
Table 5-4. Repairing the C276 Main Board (2/3)
Problem Cause
The printer does CR1 is
not operate at all. defective.
Carriage operation IC9 or IC2 is
is abnormal. defective.
Troubleshooting
Checkpoint Solution
Check the oscillator signal at If the signal is
pins 1 or 3 of the CR1. not correct,
replace the CR1
(or replace the
main board).
Otherwise,
replace IC2.
• Check input signal
If the input
waveform (CH1) at pins 6,
signal is not
5, 17, and 16 of IC9.
correct, replace
• Check output signal IC2 (or replace
waveform (CH2) at pins 8, the main board).
1, 18, and 11 of IC9. If the output
signal is not
correct, replace
IC9.
Repairing the C276 Main Board
Table 5-5. Repairing the C276 Main Board (3/3)
Problem Cause
• Check input signal waveform at
Paper feed is IC1 is
pins 1, 2, 23, and 24 of IC12.
abnormal. defective.
• Check output signal waveform
IC12 is
at pins 6, 3, 18, and 21 of IC12.
defective.
No data is IC2 is Check the output signal waveform
printed. defective. at pins 31 and 32.
• Check the voltage waveform
A particular IC1 is
(CH1) at port HD1 - HD18 of
dot fails to defective or
IC1.
print. one of the head
drive • Check the voltage waveform
transistors is (CH2) at the collector or emittor
defective (Q2 - side of each transistor.
Q19).
Revision A
Checkpoint Solution
If the input
signal is not
correct,
replace IC1 or
IC2. If the input
signal is
correct and the
output signal is
not correct,
replace the
IC12.
If this signal is
not output,
replace IC2.
If the head
drive signal is
not output,
replace IC1 (or
replace the
main board). If
the head drive
signal is
output, replace
the head drive
transistor.
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