Reading about SX-xx50 protection modes here will make your head spin. Even just SX-1250 there are many, but none exactly like mine. This is a bit different. First the symptom: Turn it on, it will play fine for an hour, loud or soft, Pink Floyd or David Benoit, then go into protection. It will come back out after a few seconds, then back into protection. The cycle will repeat with a decay in play-time, until it stays in protection. Turn off, let it sit for a couple of hours and the cycle will repeat: long time before the first time it goes into protection. Now the history: This is a favorite old piece of mine, has been in storage, but my current use-it-or-sell-it mode has me pulling things out to see if I still like them enough to keep. I pulled it out a month or so ago, opened it up, checked the Power Amplifier board voltages and Stabilizer board voltages per the manual and all was fine, so I put it in service. I decided I like it enough, but the shrink-wrap on a couple e-caps on the power board is receding so I figured it's time to go through it. I spent a few days going through Mark's list here and the schematics, decided to start with restoring the PS board, Stabilizer board, and Power Amp boards so I ordered the parts for these boards (all caps and semis). Not installed (yet). When the trouble started, I put it on my bench, checked the same voltages mentioned above, all still stabile. I pulled the amp boards and replaced C11 and Q11 on both boards hoping for a quick-fix so that I could go back to restore mode. No joy, same failure, playing quietly on my little bench 2-way speakers. It played fine for a couple of weeks before this started. My speakers are efficient 8ohm JBLs and I don't run it hard, nothing in the receiver appears to be getting unusually warm and both channels were running about the same temp. I have also gently freeze-sprayed the semiconductors on the PS board and stabilizer board after failure to see if this would quickly return it to operation, no change. Seems more like a cap is breaking down and it takes some time to "reset" to the long-play point again. Finally, my question: I'd like to repair before restore, ... if I can. OTOH, if a restoration using the parts that I have already bought and plan to install will resolve the problem, ... it does avoid that pesky troubleshooting phase. So does this failure mode look familiar enough to anyone that you can point me directly to a measure and repair? Should I just rebuild the power and stabilizer boards and see if it is now happy? Thanks to anyone who spent the time to read this far, and especially (in advance) to anyone who has a solution for me.