Yeah, the amp was originally working okay. And then it wasn't. I don't know if I touched the polarity switch and somehow messed it up. Now I get no sound-but I am wondering if I even have the speakers connected to it the right way. But yeah, I kind of thought the polarity had something to do with the grounding. So that is why I haven't touched the amp-just in case it is backwards. I just wonder if there is a way I could tell which position the switch should be in?