I have a CDX-727 Sony cd changer which stopped working last week. Nice thing is it has a one year warranty, too bad that ran out last month. Anyways, does anyone know how to eliminate the head unit as the problem or how to diagnose what really is not working? I have already hit the reset button on the head unit and have disconnected and reconnected the control cable, but still nothing. They want $200 to repair it, for that I'll just buy a new one, anyways any suggestions?