Epson LQ-2170 Service Manual page 135

LQ-2170 Service Manual
Table 5-7. Repairing the C165 MAIN Board Assembly
Problem
The printer
does not
CRU1 is defective.
operate at all.
IC11 or IC1 is defective.
Carriage
operation is
abnormal.
IC2 is defective.
Rev.A
Cause
Check the oscillator signal at pins 26
or 27 of the CRU1
Check input signal waveform (CH1)
at pins 6, 5, 17, and 16 of IC1.
Check output signal waveform (CH2)
at pins 8, 1, 18, and 11 of IC12.
Check the output signal at pins 65, 64,
63, 62 of IC2
Checkpoint
Troubleshooting
Solution
If the signal is not
correct, replace
IC1 ( or replace
the main board).
Otherwise,
replace CRU1.
If the input signal
is not correct,
replace IC1 (or
replace the main
board). If the
output signal is
not correct,
replace IC12.
If there is no
output signal,
replace IC2.
5-13