This was probably the easist repair ever. Turns out the shaft of rotating ring assembly that fits over the turntable motor was cracked, so the motor was unable to enage the ring assembly to move it around.
1. lift off (remove) the round glass tray
2. remove the old rotating ring assembly. There was a cracked plasti
... Read morec piece of it still on the motor shaft that I removed with a pair of pliers.
3. slide on the new rotating ring assembly - be careful of the orientation.
The carousel stopped rotating on my microwave oven because the plastic assembly that rotated underneath the platter had split at the point where it fit on to the rotating shaft underneath the floor of the microwave. I ordered a new plastic assembly and popped it on to the shaft. Problem solved in less than a minute.