I have an 03' 4Runner. While driving to work today, my radio just stopped working. I didn't touch it or anything. It just suddently stopped working. There's power and I can change stations, but there's no sound coming out. I put in a CD and I can see the tracks playing, but there's not sound. When I move the volume control, I don't see the volume settings changing at all. Anyone know what the problem can be?