Microwave makes loud grinding or scraping noises when the turntable rotates.

Safety: Unplug the microwave before removing parts.

• Remove tray and support: Take out the glass tray and the plastic support ring with wheels. Clean all parts and the cavity floor thoroughly.
• Inspect wheels and ring: Check for flat spots on wheels, broken sections of the ring, or melted plastic. Replace the support ring if damaged.
• Check coupler: Ensure the coupler sits firmly and is not rubbing against the cavity floor.
• Reassemble and test: Reinstall the support ring and tray, ensuring they are seated correctly, then test with a light load.

If noise persists: The turntable motor or its mounting may be worn and should be inspected by a Bosch technician.