So today my 92 SC300's radio (pioneer) decides it is going to work if and when it wants to. Before today it has worked without a hitch, but now it will turn on for a bit then just shut off and stay off for a while. I checked all fuses(multiple times), and even had the whole head unit out 2 times(to check the ground and connections, everything seems good to me). Now my question is, the radio will work intermittantly, but then will turn off without warning and stay off until it feels like coming back on...but every time the radio won't turn back on and is seemingly dead, it will always spit the tape out...Bad head unit?

 

That's what it sounds like to me. I'd want to see whether it would power up on a bench / harness, so you could rule out flaky wiring in the car, but yeah, my guess would be some internal problem in the head unit.