Why is My Microwave Sparking? Top 3 Causes of Arcing

Introduction to the Problem

You turn on the microwave and instantly see terrifying flashes of lightning and sparks inside the cavity, accompanied by a loud buzzing noise. This is called arcing.

In this guide, we cover Why Your Microwave is Sparking and How to Fix It. At Prime Cool, our expert technicians resolve this dangerous appliance breakdown daily across Pune.

Key Causes in 2026-2027

1. Metal Inside the Microwave: The most obvious cause. Even a tiny piece of aluminum foil, a fork, or metallic paint on a ceramic plate will reflect microwaves and cause sparks.
2. Burnt Waveguide Cover: This small, cardboard-like square on the inner wall protects the magnetron. If food splatters on it and burns, the carbonized food will arc and spark wildly.
3. Exposed Metal Cavity: If the protective paint inside the microwave chips away (often under the glass turntable), the exposed steel will spark when microwaves hit it.

Expert Troubleshooting & Safety Warning

If the waveguide cover is burnt, it is a cheap and easy part to replace. Do not use the microwave until it is fixed, or the sparking will permanently destroy the expensive magnetron tube.

Ensure your appliance is safe. Book a rapid microwave repair with Prime Cool.