Microwave sparks or arcs inside the cavity during cooking.

Safety First: Stop the microwave immediately and unplug it if you see sparks.

Steps:

• Remove metal: Ensure no metal utensils, twist ties, or foil are inside (unless the manual explicitly allows certain foil use).
• Inspect waveguide cover: Look at the small mica or plastic cover on the side wall (waveguide cover). If it is burnt, cracked, or has holes, it must be replaced.
• Check cavity paint: Inspect for chipped or burnt paint exposing bare metal, especially near corners and rack supports.
• Touch-up paint: For minor chips, use microwave-safe cavity touch-up paint approved for high temperatures.
• Replace waveguide cover: Install a new Frigidaire waveguide cover if damaged.

Note: If arcing persists after these steps, a technician should inspect the magnetron and waveguide for deeper damage.