• ** REMEMBER! **The microwave can still shock you even unplugged!!

    ALWAYS discharge the high-voltage capacitor first if you even think your hands will come close to any HIGH VOLTAGE components.

    Jeff mentions this: Anything in the high voltage ( magnetron, capacitor, diode, wires to and from ):
    ...Use a metal ( not the shiny chrome type ) screw driver with a insulated handle to short across ( touch both at the same time ) the terminals of the high voltage capacitor to discharge it.

    From Jeff's site: http://www.applianceaid.com/component-testing.php

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Jenn air no convection


Premium Member
Aug 27, 2008
Jenn air mod# JMC9158BAB microwave oven with convection, the microwave works fine but no convection. Able to select convection the convection fan turns and the control board displays convection. The heating element and safety thermostat have continuity,but no voltage to the element. I'm betting its the control board, there was no schematic or tech sheet so I don't know what other components may be in the circuit


Appliance Tech
Nov 16, 2007
Portland, OR
You are probably correct about the control
board if the rest tests OK. Using a meter, check for voltage from the red wire connected to the element to the chassis. If all is well, you should read line voltage. If not, then there is a problem with the black wire as it should always have line voltage on it. The red wire plugs into a relay on the control board which when closed provides the neutral path and a complete circuit. You can check the back of the board for a bad solder joint, but you may need to replace the board. Check it out and let us know.