i took one of my amps to a pawn shop, the guy tested it and set one of the channels is blown. its a mono one channel amp, so how can one channel be blown? im asking because i stopped using this amp cuz it felt like it lost power, now my new amp is doing the same thing. sounded great for a day or two now the power output seems to be lowered, as if either the - or the + on the amp is blown. but if so, wouldnt it not work at all?