I am having a similar problem and would appreciate some help. I have a Sony AM/FM Compact CD Player (Model No.CDX-HS70MS) and a 6-CD Changer (Model No. CDX-T69) installed in a boat. All was working fine. Turned it off for the night but when I turned it on in the morning, I have no sound from the CD Changer. I have sound from radio and from the single CD built into the AM/FM radio, but nothing from the CD Changer. I too have an ATT button on a remote control and also on a marine remote commander. Is it possible that the ATT button on one of these units is activated and only muting the sound from the 6 CD Changer and not also affecting the sound from the radio or single CD built into the radio? Any other reasons why I have lost sound from only the CD changer?