Samsung Microwave Sparking Inside — Causes & Fix

What Does This Error Mean?

Sparking inside a Samsung microwave is most often caused by metal in the cavity, a damaged waveguide cover, or a failing magnetron. Stop the microwave immediately when sparking occurs — continuing to run it can cause permanent damage or fire.

Affected Models

Samsung Over-the-Range Microwave
Samsung Countertop Microwave
Samsung ME Series
Samsung MS Series

Common Causes

Metal utensils, foil, or metallic trim on dishes inside the microwave
Damaged or burned waveguide cover (the flat panel on the cavity ceiling or side wall)
Burned food debris on the cavity walls or waveguide cover
Failing magnetron causing arcing inside the tube
Chipped or cracked interior enamel paint

How to Fix It

Stop the microwave immediately.

Press Stop or open the door as soon as sparking begins. Continuing to run the microwave while it is sparking can damage the magnetron, burn the waveguide cover, or cause a fire.
Remove all metal from the cavity.

Check for metal utensils, aluminium foil, dishes with metallic trim or gold/silver paint, and twist-ties. Anything metallic inside a microwave will arc — this is the most common cause of sparking and is completely preventable.
Inspect and replace the waveguide cover.

The waveguide cover is the flat rectangular panel on the ceiling or side wall of the microwave cavity. If it is brown, burned, or has holes, it must be replaced before using the microwave again. Replacement covers cost $5–$15 and are easy to swap.
Clean the cavity thoroughly.

Burned food debris on the cavity walls can absorb microwave energy and cause arcing. Wipe all interior surfaces, paying particular attention to the top and the area around the waveguide cover.
Inspect the enamel coating.

Chips or cracks in the interior enamel expose bare metal, which arcs when microwaved. Small chips can be repaired with microwave-safe enamel paint. Large areas of damage may make the microwave unsafe to continue using.

When to Call a Professional

If sparking occurs with no metal present and a clean, undamaged waveguide cover, the magnetron is arcing internally. This requires technician repair or microwave replacement — do not continue using it.