Sparking
LG Microwave
Severity: CriticalWhat Does This Error Mean?
Sparking inside an LG microwave is most often caused by a damaged waveguide cover, metal in the cavity, or burned food residue. Stop the microwave immediately when sparking occurs — continued use can damage the magnetron or cause a fire.
Affected Models
- LG Over-the-Range Microwave
- LG Countertop Microwave
- LG LMV Series
- LG LMC Series
Common Causes
- Damaged or burned waveguide cover inside the cavity
- Metal utensils, foil, or dishes with metallic trim inside the microwave
- Burned food residue on cavity walls or waveguide cover absorbing energy
- Chipped interior enamel exposing bare metal
- Failing magnetron arcing internally
How to Fix It
-
Stop the microwave immediately.
Open the door or press Stop as soon as you see or hear sparking. Continued sparking damages the waveguide cover, scorches the cavity, and can destroy the magnetron.
-
Remove all metal from the cavity.
Check for metal spoons, foil, dishes with gold or silver decorative trim, and metal twist-ties. Metal is the number one cause of sparking and is completely avoidable.
-
Inspect and replace the waveguide cover.
The waveguide cover is the flat panel on the inside ceiling or side wall of the LG microwave cavity. If it is brown, burned, or has holes, it must be replaced. Replacement covers cost $5–$15 and simply clip or slide into place.
-
Clean the interior thoroughly.
Carbonised food residue absorbs microwave energy and causes arcing at the burn spot. Wipe all interior surfaces with a damp cloth, paying particular attention to the area around the waveguide cover and any visible scorch marks.
When to Call a Professional
If sparking occurs with no metal present, a clean cavity, and an undamaged waveguide cover, the magnetron is arcing internally. Stop using the microwave and contact a technician — a failing magnetron is not safe to operate.