Synchronous Motor

I had previously determined the like culpit was the synchronous motor. The roller guide had flat spots on each roller. Order parts from Part Select - pretty good price, parts were delivered in 3 days - much faster than I expected. Printed out a parts diagram from their website and grabbed my screwdriver. Also needed a pair of side cutters to cut the metal web that held the motor cover in place - only need to unscrew screw that hold the cover in place (bottom), cut the metal connectors, remove the plate and unscrew the screw holding the motor in place, pull out old unit, replace with new motor and secure the motor with the screw. Put the cover in place and secure - put the microwave back on the counter, pluf it in, put something in the oven and start her up. Took less than 15 minutes and cost me $50 for the parts. Great deal and easy to do.

Turntable in the microwave stopped turning.

The turntable made a clicking noise, sometimes turned in the wrong direction, and wouldn't turn when there was any weight on the plate. Nothing appeared broken in the 3 spoked thing on whcih the plate sits. I replaced the motor, but this did not fix the problem; everything works fine until I put on the plate or any food on the plate. I now suspect that the wheels of the 3 spoked thing have worn down. They have flat spots on them. They don't turn when the motor turns, but drag. I suspect that this drag was what striped my first motor. I will next replace the 3-spoked thing.

Removed the back plate, removed the old motor and re-attached the new motor and the back plate. Took about 5 minutes. Works great.
Lesson learned - DON'T let your spagetti boil over.