Microwave runs but makes loud buzzing, humming, or crackling noises, sometimes accompanied by a burning smell.

Safety Warning: If you see sparks or smell burning, stop the microwave immediately and unplug it.

User checks:

• Inspect interior: Look for burnt spots, metal objects, or foil inside the cavity. Remove any metal and clean thoroughly.
• Waveguide cover: Check the small mica or plastic cover on the side wall (waveguide cover). If it is burnt, cracked, or has holes, do not use the microwave.
• Clean cavity: Wipe all interior surfaces with mild detergent and water, then dry completely.

If noise or smell persists: The magnetron or high-voltage components may be failing. Do not continue to use the microwave; have it serviced by a professional.