Microwave emits a crackling or arcing sound inside the cavity; visible sparks may appear.

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

• Step 1 – Remove metal objects: Ensure no metal utensils, foil, or dishes with metallic trim are inside. OBH Nordica microwaves are not designed for bare metal unless specified.
• Step 2 – Clean the cavity: Once cool, thoroughly clean the interior with a mild detergent and soft cloth. Pay special attention to the area near the waveguide cover (a small mica or plastic panel on the side or top wall).
• Step 3 – Inspect waveguide cover: If the cover is burnt, cracked, or has holes, it must be replaced. Do not operate the microwave without this cover.
• Step 4 – Check cavity paint: Look for chipped or burnt paint exposing bare metal. Small areas can sometimes be touched up with microwave-safe cavity paint; larger damage requires professional evaluation.
• Step 5 – Test with water: After cleaning and replacing the waveguide cover, test the unit with a cup of water. If arcing persists, discontinue use and contact service.