Microwave makes loud buzzing or humming noise when running, louder than normal, with reduced or no heating.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety warning: Loud buzzing from the high-voltage section can indicate arcing or imminent failure. Unplug the microwave.
User checks:
- Confirm that there is no metal object or foil inside the cavity causing arcing.
- Inspect the waveguide cover (mica sheet on the side wall) for burn marks or holes.
If the noise is clearly from inside the cabinet (not the turntable) and persists with proper load, the magnetron or transformer is likely failing. Internal high-voltage diagnosis and replacement must be done by a professional.
Repair Difficulty
Required Part
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