Microwave emits sparks or arcing inside the cavity during cooking.

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

• Step 1 – Remove metal objects: Ensure there is no metal cookware, foil, twist ties, or utensils inside.
• Step 2 – Clean cavity: Thoroughly clean the interior walls, ceiling, and floor with a mild detergent to remove grease and burnt food.
• Step 3 – Inspect waveguide cover: Locate the mica or plastic waveguide cover (usually on a side wall). If it is burnt, cracked, or has holes, replace it with a Bertazzoni-approved waveguide cover.
• Step 4 – Check for paint damage: If the cavity paint is chipped exposing bare metal, touch-up with microwave-safe cavity paint or have the cavity professionally repaired.