Epson LQ-510 Technical Manual page 180

REV.-A
Problem Symptom
Printer does
CPU is not
operate at operating.
all.
LQ-510
Table 5-7. SAMA Board Unit Repair
Cause
Vx voltage Check voltage waveforms for the Vx voltage and for
is not being the 24 V line.
output.
The reset Check voltage waveforms at Vx voltage and for the
circuit is not
RESET signal.
operating.
NIT signal
Check voltage waveforms for the +24 V line and for
input circuit
he NMI interrupt signal.
is dead.
Checkpoint
NM1
TROUBLESHOOTING
Solution
Replace
ZD1, Q33,
or Q34.
Replace
IC7A.
Replace
IC3B or
Q32.