• ** 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

    Jake
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FIXED KHMS2050SSS1 - every time I start the microwave, it runs successfully for a few seconds, then immediately stops and quickly resets

rickgburton

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I think maybe the inverter might be bad. The inverter and mag tube removed from the circuit, and that circuit works fine. 15 amps is a little high. That's the only thing I can think it would be.
 

robhouston

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Feb 24, 2008
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Location
Chester, NJ
Thanks, Rick. I'm going to get yet another inverter to see if that's the problem. I agree that it seems to be something in the inverter/mag circuit, instead of the controls.

I'll report back after I get the inverter and install it. If that's not it, it may be time for me to give up and buy a new microwave, at least to help keep my sanity.
 

rickgburton

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I don't think I could give up and not know what the problem was. That will drive me nuts.
 

robhouston

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Feb 24, 2008
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Location
Chester, NJ
Rick-----thanks! This is a terrific video, and very helpful. I've been very busy over the past few days and haven't had the chance to do more diagnosis. This will help me get started again over the next few days, and I'll be sure to report back.

As you mention above, it's driving me nuts not having figured out what is happening........
 

robhouston

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Feb 24, 2008
Messages
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Location
Chester, NJ
Okay, this is finally resolved! Because of various work and life issues, I had to set this problem microwave aside for three weeks. In the meantime, I was lucky to locate a similar microwave (this one with the convection oven option) on Craig's List, and I took a chance, since because of the somewhat unusual size configuration, another model would have required some cabinetry and back splash changes in order to meet the Wife Acceptance Factor. The substitute microwave was priced very low and works and looks fine, so it took some pressure off of fixing this one.

Anyway, I finally had a chance to get back to looking at this one. As Rick mentioned, it was driving me crazy not knowing what was wrong. It's always good to step away and come back with a fresh mind, and a couple of weeks apparently freshened my mind.

I started going through all of the steps I've taken from the original replacement of the keypad and related User Interface Board to fix the "ghost" beeping and program changes, and I realized that the intermittent reset problems happened after the replacement of those boards. And of course, the replacement of the boards required removing the door and reinstalling it, in my case, multiple times. So, I inspected the wiring carefully and saw some slightly crushed areas where the wiring might have become caught in the hinge when reinstalling the door. Testing showed that one wire was in fact very intermittently losing continuity. So, I spliced that crushed area, soldered the wire and covered it with shrink wrap. Everything worked properly after testing, and it continues to work after I put everything back together.

So, I've learned my lesson ----- Check the relatively simple things first, and be sure to think back through all of the steps you've taken previously. If I had done that earlier, I could have saved myself a lot of grief, and I wouldn't have an extra microwave.

Thanks to Rick for all of the valuable suggestions! This website was very helpful in all of my struggles.
 

rickgburton

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Now we know what caused it, appliance gremlins! ...lol I'm glad I could help. Thanks for the update!
 
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