Grrrr. Thanks fridgidaire!

Built in microwave installed by our homes PO, but it's very new. Says right on the inside that it was manufactured in 12/2016.

Last year around this time it needed a door switch. So I replaced it, fine.

Today, it blew the breaker again just like it did when it needed the door switch (almost). Last year when the door switch was bad, starting the microwave would blow the breaker. Now, closing the door will blow the breaker, or, if the door is closed already the breaker will immediately re blow. Hmmm.

So I take it back apart, and find that the same switch is burnt again. Ok, but why are we burning switches, and why is it blowing the breaker without cooking now? I looked at the crappy schematic on the rolled up paper that someone stuffed into the inside of the control box (nice, thank you btw). It would appear that with the door closed, my switch in question should be open, preventing a short. But also, unless the microwave was running, the main relay should be open, preventing a short.

well waddaya know? Main relay is reading "closed" when I think it should be open. But diagram is crappy, and I'm really not sure if it's a normally open relay or normally closed. So I read the part number on the relay and search it. Sure enough, relay is normally open. So there's the smoking gun (hopefully). 

Current theory is that the relay stuck open, and that a few good short events burned the switch. However, nothing to say really that the true problem isn't further upstream, burning the relay. Time will tell.

but the real rant is here:

new control board is 200+ (whole damn new microwave is about 300). Refurb control board is 100. Relays are dirt cheap. Like $10 for 10 relays cheap.

BUT! According to mouser, the relays have been obselete since the manufacturer stopped selling them IN 2014!!! This microwave was built december 2016. So yes, replacement relays are available, but only on ebay from shady chinese resellers selling old stock, and shipping expected to be here by early may (if they ever figure out the suez canal or something).

so, pay $300 and get a brand new microwave, and spend afternoon installing it. Pay $100 and wait about a week, or pay $5 and wait for who knows when and then desolder and resolder the control board while hoping I don't screw up something else. 

and, I have zero confidence that any of the above solutions will be any more reliable than the others. Joy.

anyone have one of these laying around?

https://www.mouser.com/ProductDetail/Song-Chuan/302P-1AH-C-12VDC?qs=b4gJvg5HYEuj3yhMJ6uL1A%3D%3D

My solution: call up whatever contractor you see in your neighborhood often for rehabs and ask if they have any microwaves that they'd trade for a case of beer. 
 

Otherwise, microwaves seem to be the appliance that is most likely to nickel and dime you, and the price you pay doesn't matter. I'd replace it if the fix isn't easy, obvious, and cheap. 

Option D: turn the offending microwave into a spot welder.  Do it in the kitchen in front of the other appliances so they get the message. 

https://mad-science.wonderhowto.com/how-to/turn-microwave-oven-transformer-into-high-amperage-metal-melter-0140772/

Also, with this option I guess you have to buy a new microwave. 

In reply to Robbie (Forum Supporter) :

I had a nearly identical experience, although I'd have to go check the brand. We bought ours brand new in June of 2013, and in 2019 it developed similar symptoms & I discovered the door switch was bad. I found a couple good used ones on eBay, installed them, and it immediately blew the breaker again. So it's been sitting in the garage on my workbench partially disassembled since then & is now buried under other crap. I had intentions of salvaging the steel case or anything else I thought might be useful for the Challenge, but that hasn't happened. I should probably just drag it out to the curb. 
 

Fortunately we had a stash of smaller cheap microwaves & it's been working fine for almost 2-years. 

I'm learning that they pretty much all fall somewhere in between "suck" and "hardcore suck."

In my search for a new/used washer/dryer, I'm reading pro reviews, talked to two independent appliance repair guys, and I'm learning that pretty much anything Samsung is instant death, Maytag/Whirlpool will die quickly and you have to buy their incredibly specific proprietary parts, LG is average at best.... They're all just awful.  I was reading about one of the Samsungs that if you plug it in before you turn on the water, it basically bricks.  One of the complaints about one of the LG models is that if you don't pair it properly with an app (seriously... who needs a wifi app for a dryer?) it can cause issues.

Long story short, I'm buying an old Kenmore set.  Parts are available, cheap, and mostly not proprietary.  They have dials and a button.  No computer, no fancy water pressure sensors, just fill, stir, spin.

In reply to Curtis73 (Forum Supporter) :

I got a guy that picks up old washer/dryers on the side of the road and fixes them.  $100 each for something that'll last about forever.  If something breaks it's like a $20 part.

In reply to Robbie (Forum Supporter) :

My microwave has been possessed for a few years.  You can hit the 1 minute and the plus 30 secs.  I'm a cheap SOB so since it works haven't replaced it.

Curtis73 (Forum Supporter) said:One of the complaints about one of the LG models is that if you don't pair it properly with an app (seriously... who needs a wifi app for a dryer?) it can cause issues.

We've got a fancy LG pair.  We've never paired it or installed an app and it works great a coupe of years in.

Having a quiet washing machine is wonderful.

Do you have counter space for a microwave? If so I can loan you my panasonic until you get your repair parts. We owned this microwave for 5 years or so and didn't want to part with it (because it's awesome) when we moved to our house kinda mainly in case we ran into your current predicament. It's big. Same size as the built in over the range ones.