Lu V Deerfield Beach , FL September 20, 2014 Appliance: Jenn-Air Over The Range Microwave JMV9169BAS Jenn-Air Microwave Jmv9169bas: There were no eric coach do you microwave it appeared to be functioning normally it just simply was not able to eat food. How to replace Microwave High Voltage Transformer. I first began troubleshooting by checking the diode. The high-voltage diode unfortunately does require a ohmmeter that has the capability of utilizing more than 9 V. The trick is to put another 9 V battery in line of the leads. But just to be sure I ordered a diode just in case I was wrong. I also ordered hey capacitor and high-voltage transformer just in case I was wrong as well. My first suspect was the Megatron and that is the first item I replaced when I receive my parts and bingo that was it. Interestingly enough, the magnetron looked absolutely in good shape when I pulled it out but I guess since it is a tube it can fail. Ohm meter measurements revealed no issues at all. 5 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes