M
Michael Fiedler
I had promised I would post this to the archives for future use when I
figured it out. My Realistic STA-860 receiver , catalog 31-2097 had
failed. The unit had no output. I changed about 40% of the
electrolytic capacitors in the unit, which were bad either due to
leakage, bad ESR or low values. That didn't repair unit. The problem
turned out to be the selector switch for functions. The switch is
made by Alps, and is no longer available from either Alps or Radio
Shack. The problem was the little brass fingers in the sliding part
of the switch were bent and causing it to short out each of the
functions of the switch. I tried bending them back, but they are so
fatigued that they failed after about 6 clicks of the switch. I ended
up removing transistor 611, which is a 2SC1845. The transistor was
used on the output of the switch to shut down the audio in the
receiver so there was no pops while turning the switch. I have not
experienced any pops while turning the switch after removing the
switch, but I do keep the audio down to be sure. Amp works great now!
I also have a schematic if anyone is ever looking for one.
Mike
figured it out. My Realistic STA-860 receiver , catalog 31-2097 had
failed. The unit had no output. I changed about 40% of the
electrolytic capacitors in the unit, which were bad either due to
leakage, bad ESR or low values. That didn't repair unit. The problem
turned out to be the selector switch for functions. The switch is
made by Alps, and is no longer available from either Alps or Radio
Shack. The problem was the little brass fingers in the sliding part
of the switch were bent and causing it to short out each of the
functions of the switch. I tried bending them back, but they are so
fatigued that they failed after about 6 clicks of the switch. I ended
up removing transistor 611, which is a 2SC1845. The transistor was
used on the output of the switch to shut down the audio in the
receiver so there was no pops while turning the switch. I have not
experienced any pops while turning the switch after removing the
switch, but I do keep the audio down to be sure. Amp works great now!
I also have a schematic if anyone is ever looking for one.
Mike
