Don’t buy a new microwave just yet! I thought for sure we were going to have to buy a new one especially since Nea, our dog, could find nothing wrong.

Nea (dog) visually inspected the microwave and found no problems whatsoever
We have these fancy appliances with a touch screen display (sometimes I miss the old school turn dials). Anyhow, our power went out one afternoon. It seems to happen all the time where we live so I didn’t think much of it. That is, until my wife called me saying the microwave wouldn’t work.
Full Reset
That evening, I checked things out and the touchscreen display was on, but completely unresponsive. I tried looking for some combination of “reset” in the owner’s manual and couldn’t find anything. So I flipped the circuit breaker to cut all the power. My thought was that if left the microwave off long enough, all the internal capacitors would fully discharge and other components would reset to due an extended power loss. And it worked, or so I thought! A few hours later, I got back around to this project and so I flipped the breaker back on and the display did a bunch of diagnostic stuff and came back on. BUT it was still unresponsive. Argh!! Being what seemed to be an electrical issue (from a power outage/surge), I felt confident it would be less expensive to just replace than have a tech come out, work on it and perhaps still be unable to fix it. A bit of perfect timing I suppose, Val’s dad had come by that evening and steered me to the idea that perhaps this was all just a case of a blown circuit board and it would be worth checking out.

This is the fancy display that came on, but did not work at all (this picture is after I fixed it, I’m happily heating up a piece of pizza on the dining room table)
Removal
Unhinging a microwave is no fun task, but a few bolts is all it took to pull it down from the counter. We have one of those hanging microwaves, not a counter-top model. I had to take out about twenty or so screws to remove the microwave’s metal encasing.
Final Fix
After taking the encasing off, I found two fuses near the top of the microwave and I thought I’d check those out. Unfortunately, the manufacturer had put strong tape all over the outside of each fuse, so you could not see if either was severed. I bet they do that so you have to call out a tech. But I figured both were probably still ok since the display was lit, even if unresponsive. I guessed they had absolutely nothing to do with the display or they were working and not the source of the issue.
I found the circuit board that seemed to be right on the backside of the touch screen display. I was hoping to see it charred in smoke or have some physical indication that it needed to be replaced. But there wasn’t anything obvious. So I began pulling out all the cables and plugging them back in to see if that worked. Nothing. I felt defeated. But I did notice one cable I hadn’t tried, the white one highlighted below.
I re-seated it, turned the microwave back on and everything started working again. The display was on and responsive!!!
And who help me put in the microwave that evening? My wife! She loved it. Not! But she did like not having to replace the microwave.
So if you ever find yourself in a similar situation, maybe give this a try before calling a tech or replacing a microwave. Just be careful, let capacitors and other components discharge before working with it. Read the warnings on the microwave, don’t shock yourself or injure yourself by touching parts you shouldn’t touch.