The microwave runs but doesn't heat
The most common microwave fault. Main cause: a burnt magnetron (which generates the microwaves), or a faulty high-voltage diode or capacitor. Important: a microwave has a high-voltage capacitor that holds a dangerous electrical charge even after the power is unplugged — so it should only be opened by a specialist who discharges it safely. We check the magnetron and high-voltage circuit and replace the faulty part.