I recently picked up a Technics SA-420 from Goodwill for $25. Of course, it doesn't work. No sound comes from the speaker outputs or the headphones, with the exception of a very very faint signal, only on full volume, from the tuner through the headphones. The unit powers up, goes through pre-heat, then switches green to auto, but there's no relay click. From looking at other forums, this sounds like a failed relay.
SO, I tried to short relay terminals to see if that's just it. When I shorted the bottom of two terminals on the 'switch' side of the relay, I did get the left channel to play. So logically, I switched my junk test driver over to the right channel and tried shorting the other relay terminals only to find that that caused sparking, loud noises, and permanent VC rubbing on the test driver. Is there anyone with more amp repair experience that can suggest anything?
FYI, on the attached: the green line is the terminals shorted that produced music from the speaker output. The red is the set of terminals that put my driver into convulsions. The sockets circled in yellow WERE connected when testing, and they're now empty after attempting unit disassembly to replace the relay.
Thanks,
Greg
SO, I tried to short relay terminals to see if that's just it. When I shorted the bottom of two terminals on the 'switch' side of the relay, I did get the left channel to play. So logically, I switched my junk test driver over to the right channel and tried shorting the other relay terminals only to find that that caused sparking, loud noises, and permanent VC rubbing on the test driver. Is there anyone with more amp repair experience that can suggest anything?
FYI, on the attached: the green line is the terminals shorted that produced music from the speaker output. The red is the set of terminals that put my driver into convulsions. The sockets circled in yellow WERE connected when testing, and they're now empty after attempting unit disassembly to replace the relay.
Thanks,
Greg
