Epson LQ-510 - Power Supply Troubleshooting

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