The Audio 20 system seems to work fine with radio, cd, telephone but I can get no sound from the system. The amplifier in the trunk (Harman/Becker) seems to be getting the Fiber Optic Signals. It also seems as though the amplifier is sending a fiber optic pulse back. With the fiber optic cable disconnected there is one long pulse followed by four fairly quick pulses, a slight delay followed by another quick pulse. Does this sound like an amplifier problem or an optic ring issue. There is no satellite radio or disc changer and every other option appears to work, including Bluetooth.