# Microwave issues



## IPSC (Jun 8, 2018)

Guys:

I have a Kenmore over-the-oven microwave... model 790.80323310. It is about 3 years old. This morning, as I set the timer for the food to be cooked....and touched the "Start" button.....I heard a "CRACK".... and it went dead. Can't start. Seems like something shorted or failed. I looked at the home circuit breaker box, and sure enough, this dedicated breaker tripped. Reset it.....tried again...same result. NOTE: the oven lights and fan still works....the clock needed to be reset after resetting the breaker.....so I DON'T think its popping an internal-to-unit fuse. Maybe a magnetron, or diode or something else?

So the questions:

- What is your take on all this?

- I am fairly understanding of mechanical and electrical things....but don't often get into microwaves. Seems there is a capacitor that might still be charged that can pose a danger if I take this apart and try repacing the damaged part. Comments or thoughts? If I don't discharge the capacitor, what precautions should I take?

- From this short description, what do you think is the likely cuplrit? How do I go about troubleshooting this? Thanks.


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## Nealtw (Jun 22, 2017)

I found this.








Kenmore microwave model # 790.80323310. Microwave trips


Kenmore microwave model # 790.80323310. Microwave trips breaker when you press start. What is causing this? - Answered by a verified Appliance Technician




www.justanswer.com


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## IPSC (Jun 8, 2018)

Thank you for directing me to this link....seems like an odd answer.....one would expect a bad transformer or magnatron. How do I prevent getting zapped from the capacitor? Will having the unit unplugged for ____ time be enough to discharge it? OR....simply don't touch it?. Thanks !!!!


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## Nealtw (Jun 22, 2017)

IPSC said:


> Thank you for directing me to this link....seems like an odd answer.....one would expect a bad transformer or magnatron. How do I prevent getting zapped from the capacitor? Will having the unit unplugged for ____ time be enough to discharge it? OR....simply don't touch it?. Thanks !!!!


It didn't sound right but easy to check.


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## IPSC (Jun 8, 2018)

Once I take it apart.....again.....what should I do about the capacitor and its stored charge?


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## Nealtw (Jun 22, 2017)




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## IPSC (Jun 8, 2018)

Thanks for the link to the video....but really (meaning THIS GUY !!..not you)...."here's how you do it"....and the capacitor is dead already? (!)...and then he says...."here's how you do this....but don't do this at home" 
Huh? 
Besides......"thousands of volts" that he warns you about.... doesn't kill....actually a body can take millions of volts, (think Van de Graff generator making your hair stand up).....it the AMPS that kill....so he's got some bad joojoo going on. And then....pointing to a LONG shank screwdriver as being well insulated due to its length?....ahh....no...maybe the shank should be multiple wrapped and depend more on the thick plastic handle, huh?. 
Anyway...thanks for showing me this.....I got a good idea what to do.....but this Youtube guy is unreal.


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## IPSC (Jun 8, 2018)

Again...thanks for taking the time to engage and offer help....appreciate it.... cheers.


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## jmon (Nov 5, 2012)

Imo, I wouldn't mess with taking it apart and discharging the capacitor. However, I applaud your effort. I know three years seems kind of short lived. But these units today are made very cheaply in china or mexico, and are basically throw aways.


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## IPSC (Jun 8, 2018)

jmon...in all open-ness....I am still on the fernce for what I will do next. I understand the throw away mentality as seen in today's products and such ( especially the "devices" like laptops...DON't get me going on THAT !....haha)....as much as I can, I try not to go-along with this. Things like stuff made up from melted plastic rivet heads are one thing ( never meant to be taken apart), .....but once you have electro-mechanical devices that have screwed-on comnonents and wires with spade connectors.....well.....maybe I'll give it a go. No doubt... if I find out that I need a major part that costs $250 and I can buy a decent unit for $200 to $250...well then, I might go toward buying a new one.


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## IPSC (Jun 8, 2018)

Just to give back to the community.....here is what I think is a more proper Youtube tutorial on how to troubleshoot a microwave oven....looking at various aspects. Don't know if I will take this repair route or not ( vs buying new).....but at least it'll be archived here for others to use--->


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## Priusron (Oct 25, 2020)

When my microwave quit working, the repair guy came out and started replacing things. I asked at what point they would just give me a new microwave. He stated they wont, they would just keep replacing parts. They even replaced my door. No real diagnosis other than checking vo.rage and then replacing parts.


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## BayouRunner (Feb 5, 2016)

Probably a bad door switch, some manufacturers design their microwaves to go to a dead short when they fail. Shorts directly to ground


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## IPSC (Jun 8, 2018)

Thanks all ....


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## bob22 (May 28, 2008)

I just short out capacitor with a screwdiver by touching one terminal to another.


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## Craig Spitler (Mar 23, 2021)

IPSC said:


> Guys:
> 
> I have a Kenmore over-the-oven microwave... model 790.80323310. It is about 3 years old. This morning, as I set the timer for the food to be cooked....and touched the "Start" button.....I heard a "CRACK".... and it went dead. Can't start. Seems like something shorted or failed. I looked at the home circuit breaker box, and sure enough, this dedicated breaker tripped. Reset it.....tried again...same result. NOTE: the oven lights and fan still works....the clock needed to be reset after resetting the breaker.....so I DON'T think its popping an internal-to-unit fuse. Maybe a magnetron, or diode or something else?
> 
> ...


I just worked on a kenmore over -the-stove microwave. Model 790.80323310. The schematic is typically stashed beside the control board inside. It shows an interlock switch that parallels the high voltage transformer. This switch is normally closed when the door is open to make sure the unit dies, due to short circuit, if you try to run it while open. When the door closes, the lower latch pin depresses and opens this switch, so the high voltage section can run. The problem is, this switch gets loose and moves so it no longer opens electrically, when the door closes. When you push start, the high voltage section is shorted by this out-of-place switch and trips your breaker. the lower door latch pin engages 2 micro switches. The lower microswitch enables the cooking process. The upper microswitch is the villain, that moves out of place. I used JB Weld to hold mine in place. I advise removing the whole Switch assembly which includes top switches. Engage the assembly with the 2 door latch pins to see where the microswitch needs to be to work. Remember it needs to be electrically open when the door latch pins are engaged or it will short the high voltage. Note: you won't be getting anywhere near high voltage with this job, as long as you pull the plug!


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## IPSC (Jun 8, 2018)

Thanks for the detailed reply. As you can imagine, this thread being so old....I went the route to buy a new one, but I still have this old one and may repair it to sell. All good info.....but the point about pulling the plug can still get you ( saying this for any other guys reading this). The onboard capacitor can still carry a big charge for a long time after the plug is pulled, maybe 2-3 days. Nonetheless, good info here....cheers.


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