The microwave makes a crackling, popping, or arcing sound inside the cavity during cooking; visible sparks may appear.

Safety Warning: Stop the microwave immediately if you see sparks or hear arcing. Unplug the unit before cleaning.

Steps:

• Remove any metal objects, twist ties, or foil from the cavity.
• Thoroughly clean the interior with mild detergent and water, focusing on areas near the waveguide cover and corners where grease accumulates. Dry completely.
• Inspect the waveguide cover for burn marks, holes, or charring. If damaged, it must be replaced before further use.
• Check for chipped or missing paint exposing bare metal; touch up with microwave-safe cavity paint only.

If arcing continues after cleaning and replacing a damaged waveguide cover, have a technician inspect the magnetron and waveguide.