'97 Millenia Bose Radio trouble
 

I was trying to connect an amp tha I found in my garage for a boom box I was putting in the trunk. The amp didn't work and now my speakers have no sound coming out of them. Only the front center speaker has sound coming out of it. I checked all the connections and all the fuses. I don't know what happen. Can someone please give me some direction. I can't afford to rip the entire Bose system out and install a new one in. Thank you.