Microwave emits a crackling or arcing sound inside the cavity, sometimes with visible sparks.

Safety first: Stop the microwave immediately if you see sparks. Unplug the unit and allow it to cool before inspection.

• Remove metal objects: Ensure no metal utensils, twist ties, or foil are inside the cavity.
• Clean thoroughly: Gently clean the interior with mild detergent and water, paying special attention to the area around the waveguide cover (usually a small panel on the side wall).
• Inspect waveguide cover: If the mica cover is burned, cracked, or has holes, it must be replaced before further use.
• Touch-up paint: If small chips in the cavity paint expose bare metal, use microwave-safe cavity touch-up paint to cover them.
• Do not operate with damaged parts: Continued use with a damaged waveguide cover can damage the magnetron. Replace the cover with a Miele-approved part.