Microwave not heating food?

A failed magnetron can no longer generate microwave radiation, so the oven runs its timer and fan normally but produces no heat.

Likely causes · most likely first

Magnetron (2M261-M32KLP)

Call a Pro Part: $50–$150
H.V. Inverter Power Supply

Call a Pro Part: $60–$180

A faulty high-voltage inverter board fails to supply the kilovolt-level power the magnetron requires to produce microwave energy.
Waveguide Cover (Mica Sheet)

Easy DIY Part: $8–$20

A severely burned or cracked waveguide cover absorbs microwave energy before it reaches the food cavity, significantly reducing heating.
D.P. Circuit (Control Board)

Moderate DIY Part: $60–$150

A defective control board may not enable the high-voltage circuit even when a cook cycle is programmed and started.

See the faulty part in 3D.

Tap a highlighted part to see exactly why it fails, how to verify it's the problem, and how to replace it.