I have a MAC 1500 I was given (as in free) a year or so ago. It had been in an attic and I assumed it as bad/dead. This week I decided to work on it, after adjusting the amp tubes (the voltages were all over) and cleaning it I found the only real problem when using it on everything but FM is the tape monitor switch--it's sticky and will either cause one or both channels to cut out unless it's pushed in a little, so I will be replacing it. The FM tuner initially looked like it was dead--no static, nothing, but while working on it I plugged in an antenna I had and it suddenly came alive, and I spent about an hour listening to the radio on it. As soon as I get it mounted there's no FM again, just nothing. I tried adjusting the MUX pot and the mute pot, and turning the mute switch on and off and still nothing. As it worked briefly without problems is there an obvious switch or setting I'm missing?