Yeah I have checked every wire and they are all good, the only one that seems to be missing is the amp wire. but i am not sure if I have an amp. I was looking but could not find one. I have the SC-815 Premium Sound System. Also the Power Antenna wont go up.
OK, this is just a bet - but I think the internal connections within the unit may have gone bad.
Try taking it to a store, and fit something else. And see what they find.
Or, if you comfortable with one, borrow a friend's unit and check for yourself. Disconnect yours and connect the other one. If everything is status-quo (the same, not moving and no sound), the your wiring may have been disconnected.