Radio reception is a simple system - assuming you still have an antenna that is in the "up" position, your only sources of potential trouble are that its not hooked into the socket on the back of the radio, or there is a break somewhere in the cable between the antenna and the radio unit, or you live in an area where lousy reception is endemic. I would start at the antenna end of the cable and look for obvious breaks or a disconnect from the antenna. Someone who knows how to use an ohmeter should be able to tell if there is continuity (or a break) somewhere for you too.