Hi Folks,
Have one in where the motor that works the disc change mechanism was spinning it's drive belt. Replaced the belt to find motor ground to a stop. Had a good look as suspected a gear without a tooth or something jamming the mechanism - Found nothing.
Download the manual to discover it gives no clue about gear timing, though I hadn't disturbed any apart from the loading tray trying to get to the belt, and ran it without the tray - Still stuck.
Later discovered the belt can be replaced by removing 2 screws holding the rear panel with the disc check opto-couplers and lifting it out - I'm still stuck though - Chris.