Recently had an Internal PSU fail on an Icom 970. Fault was traced to a
resistor going short due to some adhesive used at manufacturing becoming
conductive with age? anyway resistor replaced gunk cleaned away. While
repairing it was noticed the circuit has an optical switch in the start up
circuit. This lost a leg when the short took place and despite repair it
appears not too work.
Havent tried Icom as they seem to be quite useless, order replacement VFO
assembly and received notch filter switch!

The device is a small black encapsulated unit, looks like a 4 legged black
capacitor! It is Neon rather than LED according to the circuit diagram.
Cant
seem to find anything on it at all on the net. Appears to have been made
by
a company called Stuaw Kigai.

Anybody got any suggestions ?
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Suggest you consider using an optocoupler with a suitable input and output
circuit added.

Not knowing the voltage levels the failed component operates at and whether
it is in an AC or DC environment,the opto-coupler's input circuit could be
tailored with a resistive network ( possibly with an added diode in case of
an AC circuit) and the output circuit with a HV transistor if necessary.

Frank GM0CSZ / KN6WH