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Microwave spontaneously turned on by its LED display

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Re: Microwave spontaneously turned on by its LED display

#51

Post by rustcleaner »

netdevnet wrote: post #49
ak217 wrote: post #8

Earlier quoted context omitted.

What was the model? I recently encountered something similar with a GE over-the-counter microwave. One day it stayed on after opening the door. I replaced the control module and the board in it looks exactly like the one in the OP photo (Midea with all of the same components), which leads me to think the fault is the same as the one described in the post.

> One day it stayed on after opening the door. So you basically got exposed to microwave radiation. That's dangerous. Have you checked in with a doctor?

It's a microwave, non-ionizing. They're pretty much easy-bake ovens which shine a monochromatic light at a color water is very black/absorptive at (a color far redder than infrared). They cook outside-in so he'd be baking his skin well before internal injury.

Re: Microwave spontaneously turned on by its LED display

#52

Post by bzzzt »

sonofhans wrote: post #11

Partially off-topic, but I’ve seen complaints in the thread about microwaves in general. Here’s the trick — buy a commercial microwave. They’re reliable, powerful, and have only a few features. They come in all sizes. You’ll put less duty on one in a month than a commercial kitchen does in one day, so it will last forever. Time is money in a kitchen so they’re powerful and fast. They tend to have very simple, direct…

That seems to be the issue with all kitchen appliances. I've had the same issue with kitchen scales. I like a digital display for small amounts, but had a few of those 'pretty design' scales fail after a year or 2 (no, it was not the battery ;). Bought one ugly thing from a company that also makes shop scales which is working for years now...

Re: Microwave spontaneously turned on by its LED display

#53

Post by HPsquared »

arghandugh wrote: post #6

We recently got rid of a four year old microwave where the magnetron turned on spontaneously and silently when the door was closed, runaway heating the box. Control panel, lights, turntable, fan, everything is idle. Manufacturer didn't consider this an interesting defect and refused to swap out-of-warranty. The lack of give-a-shit in appliances is becoming apparent.

Sounds like relay contacts stuck closed.

Re: Microwave spontaneously turned on by its LED display

#54

Post by HPsquared »

rustcleaner wrote: post #51
netdevnet wrote: post #49

Earlier quoted context omitted.

> One day it stayed on after opening the door. So you basically got exposed to microwave radiation. That's dangerous. Have you checked in with a doctor?

It's a microwave , non-ionizing. They're pretty much easy-bake ovens which shine a monochromatic light at a color water is very black/absorptive at (a color far redder than infrared). They cook outside-in so he'd be baking his skin well before internal injury.

It would be like thermal burns but deeper. The heating is more diffuse and deeper than traditional cooking methods so I'd imagine if you did get a burn, it would go deeper into the tissue than you might expect.

Re: Microwave spontaneously turned on by its LED display

#55

Post by HPsquared »

r00fus wrote: post #10

I migrated our house to a "commercial" variant of the microwave oven [1] as I was tired of all the over-engineering and annoying patterns in modern microwaves. This microwave has exactly UI element other than the door - a digital dial that goes from 10s-6m. No start/cancel, no power level, no defrost, no program mode. I don't "cook" using the oven, only reheat or very rarely heat/boil small quantities of water. The m…

A good example of "pay more, get less" being actually nice.

Porsche does this with special stripped-out models that cost more (less unnecessary stuff, less weight).

Similar thing here, "simplify and add lightness".

Re: Microwave spontaneously turned on by its LED display

#56

Post by bschwindHN »

dusted wrote: post #42

There exists only one correct design of microwave ovens. It has zero ICs. It has exactly two direct user-inputs and one indirect. The two dials select on-time and duty-cycle (cooking time and "power"). The third input is the safety switch which deactivates the cycle when the door opens. This design is the most userfriendly, the most economic and the most reliable. This is the hill I will die on.

You are exactly correct, and I'll die on that hill alongside you.

Re: Microwave spontaneously turned on by its LED display

#57

Post by kwhitefoot »

r00fus wrote: post #10

I migrated our house to a "commercial" variant of the microwave oven [1] as I was tired of all the over-engineering and annoying patterns in modern microwaves. This microwave has exactly UI element other than the door - a digital dial that goes from 10s-6m. No start/cancel, no power level, no defrost, no program mode. I don't "cook" using the oven, only reheat or very rarely heat/boil small quantities of water. The m…

I inherited my Moulinex microwave from my mother thirty years ago. Apart from the internal lamp failing it is in perfect order. No electronic controls just a power dial, clockwork timer.

Re: Microwave spontaneously turned on by its LED display

#58

Post by kwhitefoot »

bschwindHN wrote: post #56
dusted wrote: post #42

There exists only one correct design of microwave ovens. It has zero ICs. It has exactly two direct user-inputs and one indirect. The two dials select on-time and duty-cycle (cooking time and "power"). The third input is the safety switch which deactivates the cycle when the door opens. This design is the most userfriendly, the most economic and the most reliable. This is the hill I will die on.

You are exactly correct, and I'll die on that hill alongside you.

But the properly made microwave of that kind will probably carry on living after you. Mine (Moulinex) outlived my mother and has been working for me for the last thirty years.

Re: Microwave spontaneously turned on by its LED display

#59

Post by ZiiS »

barbegal wrote: post #19
goda90 wrote: post #15

Earlier quoted context omitted.

The thing is, the superior way to reheat something would usually be a lower power level. But not the standard "turn on - turn off" cycle that most microwaves do. Actual lower intensity microwaves. You need an inverter for that. The food would heat more evenly, which is especially useful for things like butter that are prone to splattering.

Pulse width modulation works just as well if the pulse width is short compared to the overall cooking time. And not having an inverter makes it more efficient. Unfortunately lots of cheap microwaves have a pulse width which is more than 10 seconds, presumably to help lifetime reliability, but means that for cooking times less than a couple of minutes it doesn't work well.

Inverter microwaves are also more energy efficient than conventional ones (though more to go wrong).

Re: Microwave spontaneously turned on by its LED display

#60

Post by BlueGh0st »

ctrlGsysop wrote: post #28

Fascinating in that our GE microwave (still actively sold) has an undisclosed feature that if you lift the door, when fully closed, by no more than a few mm, the microwave will start. I noticed this when cleaning the enclosure with a rag and my hand ever so slightly lifted up the door from the bottom. I can see how a consumer could wedge a kitchen utensil or plate accidentally under the microwave causing it to start…

A few weeks ago I noticed my cheap Toshiba microwave does the same when the door button is partially pressed. Scary! I stood there holding it just right for a very long time to make sure it wouldn't heat a cup of water.
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