Dumb Question....

[jstout66]

other than replacing tubes I am kind of "lost" on any repair, but was wondering if anybody might know what caused my radio to break. I have an RCA 1958 twin speaker table top radio. It's been recapped and was working well. I had it on the other day, and it let out a loud squeel and smoked. I turned it off and looked under the chassis. 2 resistors had burned up that were tied into the 35W4 tube socket (this radio uses the standard 5 tubes) Anyway... I tested the tubes and they were all good. So what do you think might have failed to cause this to happen? I've never had a resistor burn up in a radio or tv before. Do they just get old and fail or does something cause them to fail??