i cant be more specific than this-first check whether the mechanism is jammed or there is a fault with it, then check if the signals of syscon are as they should be
Hi movie fan , it could be a misalignment of tray mechanism .The first is to get service manual , the alignment procedure is well explicit . check the belts tamben .
"cuidado com essa mecanica , tem um monte de afinaçoes ."
A similar thing happened to mine after transporting whilst moving house.
Try taking the lid off and see if the disk spins when pressing play, mine didn't. All it needed was a gentle tap on the side of the motor and it's been ok ever since.