The plate spins, the light's on, but the food comes out cold.
The magnetron, the high-voltage diode, or the capacitor.
The capacitor holds a lethal charge even unplugged, so this is bench work with proper discharge — not a DIY job.
It depends on the model and on what we find inside, so we quote each repair individually. The diagnosis fee depends on the device, and you approve the exact repair price before any repair starts. If it can't be fixed, you only pay the diagnosis.