Microwave runs but nothing heats. How do you test the diod? Checked for continuity have none.
Answer Hello Rich. You most likely have a "high voltage" side malfunction. Transformer, diode, magnetron, Capacitor. You will need to be extremely careful if you decide to test the components with a multi meter, Very high residual voltage is present, so make sure you remove power to the microwave and short across the terminals on the capacitor. The magnetron should have a reading of less than 1 ohm resistance across the two terminals, and an "open" circuit between each terminal and chassis ground. The diode/rectifyer should have a resistance reading in one direction only, no reistance, or resistance in both directions indicate a faulry diode. The primary winding on the trans former should read approximately 450 Ohms resistance, the secondary wonding should read 80 ohms resitance, and the filament transformer should read 100 ohms resistance. If all the readings are proper and in range, replace the magnetron.