microwave started sparking while heating leftovers

Possible Causes of Sparking:
Metal in the Microwave:

Cause: Accidentally leaving foil, metal utensils, or containers with metallic trim in the microwave.

Fix: Remove all metal objects. Only use microwave-safe containers.

Food with Hidden Metal:

Cause: Some takeout containers have metal handles or metallic lining.

Fix: Transfer food to a microwave-safe plate or bowl before reheating.

Damaged Waveguide Cover:

Cause: Food splatter buildup can burn or damage the waveguide cover (usually a plastic-looking panel inside the microwave).

Fix: Inspect the cover—if it's burned or damaged, it should be replaced by a professional.

Burnt Food Residue: