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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

#61

Post by farkanoid »

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…

Doesn't seem limited to GE Microwaves! My wife uses a cheap Kmart house-brand microwave for waxwork that does the exact same thing.

I have another in the kitchen (Panasonic NNCD997) that has an interlock system which blows the primary fuse if a) The door is open and b) The magnetron is currently active.

Unfortunately, with this model, the incandescent bulb dying kills the inverter PCB.

Edit: The service/repair manual[1] for the Panasonic is an interesting read, if anyone is interested

[1] http://up.orificeworks.com/nn-cd997s_cd987w.pdf

Re: Microwave spontaneously turned on by its LED display

#62

Post by frabert »

HPsquared wrote: post #54
rustcleaner wrote: post #51

Earlier quoted context omitted.

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.

https://www.youtube.com/watch?v=3hBRxwQXmCQ This guy recklessly tested various way of getting irradiated by a microwave to see what the effects are.

Re: Microwave spontaneously turned on by its LED display

#63

Post by jaeckel »

Rinzler89 wrote: post #45
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.

>The lack of give-a-shit in appliances is becoming apparent. Because most budget name brand kitchen appliances are just rebadged Haier/Midea OEM designs. I know HN has a hate boner for Samsung and LG appliances but for me they seem to be the most trustworthy budget appliances since at least they have their own designs instead of rebadging Chinese OEM ones like the rest. Sure, if you have money you can go with a reput…

> Sure, if you have money you can go with a reputable brand like Bosch & Siemens

Just FTR they're exactly the same -- "BSH Hausgeräte GmbH" -- with just a different label on it. ... And I didn't have a single good experience in the last years, IMO they're designed for planned obsolescence.

E.g. my premium Bosch Hand mixer broke after 2.5 years. Afterwards I bought a >35 years old used RG28e for half the price and it's still going stronger than the Bosch ever was, 5 years later.

> if you have even more money you can go with Miele

If you buy cheap (or uninformed) you most likely buy at least twice.

Re: Microwave spontaneously turned on by its LED display

#64

Post by leokennis »

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…

Maybe a dumb question, but why do consumer microwaves have all these power settings (600W, 800W, 1000W) if apparently they are useless? I don't really know how microwaving works on a physical level - do I achieve the same effect by microwaving something for 30 seconds at 1000W or 1 minute at 500W?

Re: Microwave spontaneously turned on by its LED display

#65

Post by cryptonym »

leokennis wrote: post #64
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…

Maybe a dumb question, but why do consumer microwaves have all these power settings (600W, 800W, 1000W) if apparently they are useless? I don't really know how microwaving works on a physical level - do I achieve the same effect by microwaving something for 30 seconds at 1000W or 1 minute at 500W?

The waves are only heating specific parts of the product. By reducing power you let heat propagate more evenly. You can avoid explosion, for instance if the middle of a butter is melted and boiling while the outside is still cold. Or better defrost without cooking.

You can achieve the same by heating full power and doing regular pauses (which is often how this is implemented anyway).

Re: Microwave spontaneously turned on by its LED display

#66

Post by GJim »

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…

> the over-engineering and annoying patterns in modern microwaves

I walked into our office tea room one morning and saw three engineers standing around trying to work out how to use the new microwave.

No joke.

Quite why a microwave needs anything more than cooking time and power level knob is beyond me. (This thing probably has options to ping my phone if my jacket spuds go soggy).

Re: Microwave spontaneously turned on by its LED display

#67

Post by pajko »

Once had to repair my washing machine. It was easy to identify the problem after removing the control board: a single $1 chip integrating nothing more than 4 motor driver FETs cooked itself due to the lack of a heatsink. Unfortunately could not fix it because the board had a thick layer of some glue-like stuff which I could not remove, and so had to replace the whole board, doubling its lifetime to more than 10 years. It still rocks but got out of balance and is quite noisy sometimes.

Re: Microwave spontaneously turned on by its LED display

#68

Post by xattt »

neilv wrote: post #39
lozenge wrote: post #13

Earlier quoted context omitted.

The CPSC would be interested.

Maybe not. I recently did the lengthy CPSC form, to report a defective new name-brand microwave oven unit, which was manufactured with a 1/8" mis-seating of parts, where I measured with a professional meter to be leaking much more than anywhere else. A week later, I heard back: > [...] The product or particular concern that you describe does not fall within CPSC’s jurisdiction. You may wish to contact the agencies li…

When regulatory bodies fail, it’s time to kick it into the court of public opinion, i.e. the media.

Re: Microwave spontaneously turned on by its LED display

#69

Post by xattt »

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…

The magnetron is on an interlock that blows a fuse if the door microswitch is on.

Re: Microwave spontaneously turned on by its LED display

#70

Post by martin_a »

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.

I'd be interested in such a simple device, but does anybody even produce tech _that simple_?
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