• ** 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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Trying to modify Panasonic SD997S to become UV curing oven... Won't stay on..

trebor smith

Premium Member
Oct 24, 2013
United States
Model Number
I removed the magnetron and the magnetron power supply and replaced it with a 100 watt UV LED and LED driver. The power that would normally go to the magnetron power supply now goes to the LED driver, and a 12v power supply for a heat-sink colling fan. I removed the inverter power supply completely.

The problem is that it shuts off after 2-3 seconds. This is because the 3-wire CN3 is not getting the proper signals from the power supply CN701.

I was hoping I could just jump those wires, but it seems like they are some kind of pulse-width-modulated inverter feedback that is hard to fake.

Any idea how I can mod this control board to keep the power to the inverter board on for the duration of the timer? Maybe if I put the inverter power supply back and let it get energized but don't have the magnetron in place? I suspect that won't work either as it will know that the magnetron is not drawing power.


What heat setting is the control programmed for? On high I would think the inverter should be powered 100% of the time during heating. That appears to be the case on my Panasonic inverter model. It should only cycle the power on lower heat settings AFAIK.

You might also be able to tap into the power supply for the turntable motor instead. That motor should be powered continually while the micro is in cooking mode. I don't know how much power draw that circuit will handle though.

Dan O.
100%, but that is not the problem. The 120v is working fine. The issue is that when the control board doesn't see the coded PWM signals from the inverter, it shuts everything down within 3 seconds.
The issue is that when the control board doesn't see the coded PWM signals from the inverter, it shuts everything down within 3 seconds.
I wasn't aware of that function on an inverter model's control. I've never seen a conventional microwave oven control with a comparable function.

Dan O.

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