I picked up a R-500 at the local thrift shop today. $35-- expensive for thrift shop stuff when several heavy modern receivers were $15, and it had the input selection knob replaced with a clearly non-matching substitute, but otherwise not hideously dirty; all lights seem to work and it really hits the classic aesthetic in a way my beloved JVC gear doesn't . When I powered it up in the shop, I saw the signal gauge flicker at times, but no relay click. It didn't dawn on me at the time, and then I spent a while reading "the protection circuit caps like to give out" and thinking that was in front of me. I blew it out with canned air, and the first few times it went on there was intermittent popping and clicking, little sound, and no consistent relay. But now it seems to have the relay pop in more consistently on power up-- as if it's back to normal-- are there parts of the system that misbehave that way? (Reminds me of a Commodore 128DCR I bought-- it wouldn't power up the first few times, then suddenly started working) The big concern I see right now is that the "Stereo/S-lock" function works pretty erratically. I can't get stereo on many strong stations, and only a handful of stations escape muting in S-lock/stereo mode. The signal strength meter is zero on plenty of very listenable signals, and full on dead or static spots.. Using some broken rabbit ears as antenna. The SM shows DC offset adjustments, so I'll do that along with the obligatory Deoxit sprays, but is there an adjustable bias? Given it's a STK module unit, I'd prefer to keep it cool for longevity's sake-- new parts are a pain. The caps don't look bad from an immediate inspection, but the glue holding the heatsink in the "12v supply" zone of the PCB does look horrible and dirty and gungy. Also, the loudness control seems to just quiet the sound, not change its character much. Could be my headphones (those beige Koss ones Massdrop was selling a few months ago) though. Are my expectations wrong based on units with conventional loudness buttons?