microwave plate would not turn

I previously replaced the turning motor because the gears in the old one were stripped. However, the new motor did not fix the problem. Upon examining the 3 wheels of the rotating ring guide, I noticed that there were flat spots on the wheels. When the motor tried to turn the ring, the wheels did not turn, but dragged, thus causing a major friction that eventually stripped the gears of the motor. Fortunately, I diagnosed the problem before the gears of my new motor were ruined. Replacing the rotating ring guide immediately fixed the problem.