Customer Questions and Answers for Microwave High-Voltage Transformer by Whirlpool

Paul,

You will want to test the high voltage transformer, capacitor and diode to make sure that they are good. Also check the thermal fuse on the magnetron. The thermal fuse should read closed for continuity. To test the high voltage transformer you will want to pull the unit down from installation and remove the cabinet, make sure that the unit is unplugged. You will remove the leads from the terminals, Set the ohmmeter to Rx1 and touch the leads to the terminals. Primary should read less than 1 ohm, Secondary should read less than 1 ohm and filament to ground 0 ohms. You will then measure resistance on a R x 100 scale on the primary and filament for infinity reading.

For the capacitor you will remove the leads from the terminals. Set the ohmmeter to a R x 1000 scale and touch the leads to the terminals. Normal will be momentarily indicates several ohms and gradually returns to infinity. Terminal to chassis should read infinity.

For the diode, set the ohmmeter to the R x 1000 scale and measure forward resistance, normal will show continuity abnormal will be infinity. Measure the reverse resistance and normal will be infinity and the abnormal will show continuity.