Microwave makes loud buzzing, humming, or grinding noises while running, louder than normal fan noise.

Safety: Unplug the microwave before inspection. High-voltage components are dangerous; avoid contact.

• Isolate noise source: Listen carefully to determine if the noise comes from the top, side, or bottom of the unit.
• Check turntable system: Remove the glass tray and roller ring. Run the microwave briefly with a cup of water. If the noise disappears, the turntable motor or rollers may be the cause.
• Inspect fan: Access the cooling fan and check for debris or bent blades. Clean and straighten as needed.
• High-voltage hum: A deep, loud buzzing that occurs only when heating is active may indicate a failing magnetron or transformer. This should be diagnosed and repaired by a professional.

If the noise is accompanied by a burning smell or smoke, unplug the unit immediately and do not use it until serviced.