Epson PX-8 Technical Manual page 223

Measure output vol-
tages at pins 8 and 14
of IC 12D while oper-
ating RS-232C inter-
face.
Measure output vol-
tage at pin 28 of IC 9E
while reading ROM
capsule.
Turn POWER switch
OFF and make sure
that no voltage other
than VB+ is output.
Check levels of pins 2
and 15 of IC 12D.
Replace IC 4C;
GAH40M.
Check level of IC 13E
pin 31.
Check transistors
011,027, and 01.
y
Check transistors 07,
08,014,017,018,
021,and031 andre-
place defective one.
Replace IC 13E.
Replace slave CPU
6303 (13D).
y
Check signals of IC
14D pins 14 and 15.
Replace IC 14D.
5-22
REV.-A
Replace IC 12D.
y
Check transistors 04,
05, 019, 022, and
028, and replace de-
fective one.