Microwave plate not turning; food heats unevenly; motor noise may or may not be present.

Safety first: Unplug the microwave before accessing the underside.

Step-by-step checks:

• 1. Remove and clean components: Take out the glass tray and roller ring. Clean them and the cavity floor. Replace the roller ring if wheels are broken.
• 2. Inspect the coupler: Check the plastic coupler that fits into the motor shaft. Replace if cracked or loose.
• 3. Test motor operation: With the tray removed, run the microwave briefly (with a cup of water) and observe if the coupler turns. If not, unplug and proceed.
• 4. Replace the motor: Access the motor from the bottom, disconnect wiring, remove mounting screws, and install a new motor of the same rating.