How to Fix / Troubleshooting

Safety: Unplug the microwave before cleaning vents or accessing internal parts.

Improve airflow: Ensure the microwave has the required clearance from walls and cabinets. Do not block top or rear vents.
Clean filters: On over-the-range models, remove and clean grease filters. Replace charcoal filters if clogged.
Avoid long continuous runs: Allow a few minutes of rest between long cooking cycles to reduce heat buildup.
Listen for fan: During operation, you should hear the internal cooling fan. If it is weak, noisy, or not running, the fan motor may need replacement.
Thermostat replacement (pro level): A technician can test and replace the magnetron or cavity thermostats if they are opening prematurely.

If the unit repeatedly shuts down mid-cycle even with good ventilation, schedule professional service.

Microwave intermittently stops heating or shuts off mid-cycle but the display remains on; may restart after cooling.

Possible Causes