My surround wiring is completely disconnected. I don't even remember where I put the cable.

I'll check in the back tonight for any wires touching. I'm always amazed by the tangle of cable back there, even after I neatly lay it all out. I move the tube amp connections around fairly frequently as I'm always tweaking the circuit, a Dynaco ST-70 converted to 6B4G DHT in class A push-pull, so maybe I made something touch when I pulled a cable.

I can understand tubes, but modern transistor amps baffle me.