[Glinda]

Originally Posted by Glinda

Ah. Now this makes perfect sense to me. I was sure there was a house wiring component to this mystery. Thank you!

Originally Posted by tw

No house wiring is involved in this mystery (if AC electric lights do not flicker or change intensity when major appliances power cycle).

No. House wiring absolutely DOES explain a lot to me, because of the clocks that needed to be reset and the clocks that didn’t. I’m thinking that there was a very brief (a few seconds) power surge – either before or after a brief actual outage (less than 60 seconds) – and that caused my poor, elderly microwave with its ancient hardware and software features to finally short/spaz out. If the above is true, the new, digital clocks needed to be reset because they’re new and very sensitive to any super-brief outage, meanwhile my 20-year-old stovetop and microwave clocks didn’t need to be reset because they can withstand and have consistently withstood outages of less than 60 seconds without having to be reset.

Originally Posted by tw

If you had a surge, then a microwave is damaged - no longer works. And some of other less robust appliances (ie GFCIs, clocks, central air controller, door bell) are damaged.

That makes no sense at all. I’ve lived here 14 years. The previous owners (the people who built this place) lived here for 6 years. That means the newer built-in microwave and all the other kitchen appliances are 20 years old. If what you claim is true, and a power surge kills microwaves, HVAC controllers, and doorbells, why do my newer microwave, my HVAC controller, and my doorbell still work perfectly? Why haven't the zillions of power surges over the past 50 years caused my old microwave to die before now?

Originally Posted by tw

Not one reason is given to suspect house wiring or a surge. So those wild speculations are binned immediately.

Nah. It’s winter here in SW Washington. There’s weather out there – freezing temps, snow, rain, hail, sleet, and occasional, significant wind. I live in a rural area not far from the Columbia River Gorge (LOTS of wind) with above-ground power lines and forested land for miles around. Trees/branches fall onto power lines all the time.

Originally Posted by sexobon

If you read what was written, with comprehension, you'll see that no one was blaming house wiring for the malfunction.

Correct. I’m certain the house wiring didn’t cause the microwave to power on. I said that the house wiring was a component of why the microwave powered on. The reason I believe this? It has to do with which clocks needed to be reset, and which clocks didn’t.

Originally Posted by sexobon

And then there's a potential problem from cumulative damage that can make a very old microwave more susceptible to a small external surge before or after a power outage.

Exactly. Simple common sense.

Originally Posted by tw

Fact that it worked normal after power cycling implies a problem often found with real time single chip computers of that vintage. And not something created by a mythical surge.

I am not an electrician, but a 50-year-old microwave will obviously have outdated computer chips and software. And even if the chips were originally designed to handle power surges (after all, power surges did exist in the 1970s, so this would presumably have been taken into design considerations), 50 years of handling power surges surely weakened whatever hardware and software design features were originally in place. Again, I’m not an electrician; this just seems like common sense to me.

Originally Posted by tw

If a cat started it, then that microwave eventually timed out. Or a thermal safety monitor cut off power. Unlikely a cat can just happen to hit a right sequence of keys. Or even has sufficient paw strength to depress those keys.

The cat may or may not be part of the equation. I merely brought it into the mix because I don’t think it can realistically be eliminated. The cat DOES paw at anything reflective (such as the front of the microwave). As for the microwave control panel, there is nothing to “depress” other than the big press bar that opens the door; the control panel is touch sensitive and has never failed in any way. Just a light touch and it engages.

Originally Posted by tw

BTW, when one only understands how to 'wreck shit', then even "electronic rust" is proof that Martians are conspiring with the Rovers to kill us all using our microwave ovens.

I KNEW it!