This cd changer is done. Mine had the same problem I took it apart trying to repair it but was unsuccessful. I fortunatly found one that was similar at a garage sale and swaped the insides out. It works now... But for how long.
If this is a cd changer then there is a reset button inside door or on changer some where that you press and hold and it should reset system. If not then unplug from power for atleast 15min. Re-enstall
Usually answered in minutes!