Epson LQ-1170 - Page 106

REV.-A
Problem
The printer
does not op-
erate at all.
The carriage
operates
]bnormally.
Table 5-5. R
Symptom
The CPU does
not operate.
The carriage
does not op-
erate at all.
Carriage oper-
ation is unsta-
ble (lack of
torque).
air of in the Main/Drive Circuit Board (Continued)
Cause
Either ROM or
RAM is
defective.
The CPU is
defective.
IC2C is
defective.
ICI 5 is
defective
IC 152A is
defective.
Checkpoint
Check the oscillator signal at either pin 33
or pin 34 of the CPU.
Check the CR motor phase signal at pins
9, 10, 11, and 12 of
IC2C.
At IC 15, check the input signal for pin 6
and the output waveform for pin 8.
Solution
Replace IC3A
or
IC4A.
If a signal is
detected, re-
place
IC2C.
Otherwise, re-
place CR1.
Replace
IC2C.
Replace
IC 15.
Replace
IC 15.
5-17