I just bought a 1996 Cobra convertible, and there is no sound. The radio head and CD units appear to be functioning correctly. I did some research and found a blown fuse under the hood, but that did not change anything. I got to the rear amps and they seem to be okay, so I pulled everything out of the front. Everything points to the front amp, but how can I test it to confirm it's bad. I don't want to change at this time as the car is 100% stock with very few miles. I thought about buying a bypass cable to see if I get any sound that way. I do hear a hum, but it does not change with increase or decrease in volume. This is the same for AM/FM/CD.