9 ms·

Microwave spontaneously turned on by its LED display

hex4def6 2y ago
Link seems dead. wayback version: https://web.archive.org/web/20240910031602/https://blog.stuffedcow.net/2024/06/microwave-failure-spontaneously-turns-on/ https://web.archive.org/web/20240910031602/https://blog.stuf...
ThePowerOfFuet 2y ago
Unreadable on mobile. :(
hulitu 2y ago
> Microwave Oven Failure: Spontaneously turned on by its LED display It is an engineering failure. The oven is not to blame. /s
MisterTea 2y ago
Notice that door switch middle is a crowbar[1] which is there to prevent the magnetron from powering on when all else fails (and there is a lot of interlocking). My friends parents had a microwave that kept dying so I opened it up and realized one of the three switches was a crowbar and it blew the fuse. I changed the fuse and it powered on again and ran for a few more days until it blew again. They decided it was unsafe and canned it. 1. https://en.wikipedia.org/wiki/Crowbar_(circuit) https://en.wikipedia.org/wiki/Crowbar_(circuit)
- MarkusWandel 2y ago
  Ironically the switches are cheap (from Ali Express anyway) and easy to replace and TMK virtually all microwaves use the same type. But yes, when you open the door, they do the following, in order: - open to send a "stop microwaving" signal to the controller - open to physically open the power circuit to the magnetron transformer - close to short out the power after the above relay (the crowbar part) The bottom two relays (in the list, not necessarily physical order) are independent of what the control board does. If due to mechanical slop, the bottom one switches before the middle one, boom goes the fuse. Even if you're just opening the door of an idle microwave. That's why, at least in mine, it says on a label inside, if the fuse is blown, replace the door switches along with the fuse. The sequencing is very tight. You have to push the button veeerrry slooowly to actually observe the switches clicking in sequence.
arghandugh 2y ago
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.
- quesera 2y ago
  That sounds dangerous, and deserving of a name & shame. Or a YouTube video with a pack of microwave popcorn that spontaneously pops and burns and smokes.
- ak217 2y ago
  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.
  - arghandugh 2y ago
    Yep, the GE over-the-range model PNM9196SF3SS. GE is just a Haier badge since 2016. I'm not surprised by a Chinese company not giving a shit, but for a microwave magnetron to fire on its own feels like a sign of deep engineering rot. The only fix was to unplug it then swap the logic board. Once it happened again with the new board we threw it out.
    - xattt 2y ago
      I had non-stop issues with GE OTR microwaves for 2 years. I started with a PVM2188SLJC that I ended up getting replaced three times by GE over a year for separate issues (buzzing turntable, cracked casing). I ended spamming the executive team and got an upgraded model with convect for free. Fast forward two years later, and the fuse tripped inside the microwave after I forget a bottle sterilizer overnight, on Christmas Day. I said fuck this, and went and got a Panasonic NN-SG158. The twist was that it looked like it was a different version of the first GE microwave we had from the same OEM, but a little reworked.
r00fus 2y ago
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 microwave beeps only once after complete and it's not incredibly loud. Despite my kids literally abusing this device, it's been rock solid for 7+ years. Amusingly my company started putting these same exact models in our office break/kitchen areas a couple years after I bought mine. [1] https://www.amazon.com/gp/product/B00BDF5ZNS https://www.amazon.com/gp/product/B00BDF5ZNS
- sonofhans 2y ago
  Great minds think alike. That is exactly the microwave I have, and for the same reasons. Such a brilliant tool.
- goda90 2y ago
  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.
  - apricot 2y ago
    The commercial microwaves we have at work have both a large dial to set the time, and four large buttons under it for 25%, 50%, 75% and 100% power. No other controls. They are great.
    - hammock 2y ago
      If the power level buttons were an old school radio button that would be so cool
      - 2y ago
sonofhans 2y ago
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 controls, rather than a myriad of popcorn/pizza/whatever buttons. Commercial microwaves often have an integrated diffuser, so they don’t need the stupid rotating glass plate in the bottom.
- ToucanLoucan 2y ago
  Can confirm. We got a commercial-grade Panasonic microwave I believe, that survived near daily use for almost 9 years before the magnetron finally gave out. We replaced it with an identical model, and it must be a pretty good one since a cursory comparison inside between the old and new revealed virtually no changes since our old one was made. If it ain't broke...
  - MarkusWandel 2y ago
    Can confirm because at my work, they initially put ordinary consumer microwaves in at the coffee/lunch stations. They failed quickly. The commercial ones last. However the latest ones have a very flimsy feeling control wheel, I somehow imagine a 25 cent rotary encoder behind that which, if it fails, may still cause the otherwise solid machine to be discarded.
    - bzzzt 2y ago
      That's not all bad. Someone who can replace a 25 cent encoder can enjoy a lifetime of microwaving ;)
  - ssl-3 2y ago
    I cooked for a family in part with a consumer-grade, Walmart-sourced Panasonic inverter microwave oven for a dozen years until circumstances made me get rid of (donate) it. No issues ever. It was reliable, had some useful programming options (that nobody ever used but me, but it had them), and it did a good job of microwaving food in a consistent and predictable manner. (But that's not an indication that inverters are reliable, or that consumer is the same as professional, or that Panasonic is good, or of anything else really other than that anecdotes are anecdotes.)
yborg 2y ago
My microwave is a 1993 Panasonic. It sat in a basement for about 10 of the intervening years, but has been a daily driver for the last 6-7. Comparing it to current retail units, it's remarkable how little has changed in that time.
deleted 2y ago
[deleted]
Retr0id 2y ago
I have a Samsung microwave with a really weird bug. If the door is just a few millimetres ajar, it turns on by itself. It's not just mine either, a lot of reviewers point out the same. It seems to be a design flaw. It's not a huge issue, since I'm not exactly in the habit of positioning the door in a half-open state. My guess is that they have some broken/inverted logic related to the "turn off if the door is open" feature.
- solid_fuel 2y ago
  I remember this flaw in a Samsung microwave from ~2007-2008. It freaked me out when I triggered it while trying to quietly close the door.
- djmips 2y ago
  The article describes such an issue but the assures that the oven magnetron doesn't run. Maybe it's a similar problem where the turntable and light come on in that situation.
ctrlGsysop 2y ago
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 and continue to run. Zero logic protection.
- djmips 2y ago
  They mention that in the article but assure that the magneton does not run.
  - ctrlGsysop 2y ago
    Indeed, nothing is heating in this state.
- BlueGh0st 2y ago
  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.
- farkanoid 2y ago
  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 http://up.orificeworks.com/nn-cd997s_cd987w.pdf
- xattt 2y ago
  The magnetron is on an interlock that blows a fuse if the door microswitch is on.
omoikane 2y ago
One of the comments linked to an article about keyboard problems caused by a LED, which was previously discussed here: https://news.ycombinator.com/item?id=36581204 https://news.ycombinator.com/item?id=36581204 - Repair adventure: A single white LED causing stuck keys on a RN988 keyboard (2023-07-05) I wasn't thinking about the color of the LED at the time, but after reading this article, I wonder if we should prefer products with green LEDs in general, like green LEDs are just more reliable than blue/white LEDs for some reason? Also, I can't seem to find microwave ovens with red LEDs.
userbinator 2y ago
The title is a bit clickbaity, since the actual "oven" part (the magnetron) stayed off. As it should, since the safeties for it are much more robust than the other parts: I’m quite impressed by how many independent mechanisms there are to prevent the magnetron from accidentally turning on. Not only are there three door switches to ensure the door is closed, there’s also a mechanism to guard against a faulty microcontroller or software. Personally, I think the ones with mechnical controls, no microcontroller, are the most reliable and also easiest to repair.
rdtsc 2y ago
I scared myself with my microwave, a cheaper Samsung. Somehow it turned “itself” on when I opened the door once. I quickly slammed it shot and jumped back. Hopefully it’s this exact failure and the magnetron didn’t actually start.
dusted 2y ago
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.
- bschwindHN 2y ago
  You are exactly correct, and I'll die on that hill alongside you.
  - kwhitefoot 2y ago
    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.
- martin_a 2y ago
  I'd be interested in such a simple device, but does anybody even produce tech _that simple_?
- TimeBearingDown 2y ago
  Don’t forget a physical handle to pull open the door. I’d take a steam sensor as well. Thanks to Technology Connections, great channel. Convinced me to read all the fine print until I found a Breville that had it. https://youtu.be/UiS27feX8o0 https://youtu.be/UiS27feX8o0
- pphysch 2y ago
  Simple is good but another approach to simplicity would be more sensors (weight, thermal, steam, optical?) and a single "cook" button (or a menu/dial with few different cook options, defrost, warm, hot). For casual use the UX is superior as it requires less micromanagement. Also lot more difficult to engineer well, though.
pajko 2y ago
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.
reconvene1290 2y ago
Must be one sexy LED display.
ajb 2y ago
Nice investigation! My 25 year old microwave is really solid, except for the lamp, which has blown. It's an old bulb so it should be replaceable - except that physically there's no way to do it without unscrewing the magnetron, which is well into scary territory - you need to basically re-qualify it after reassembly by scanning for leaks with a professional instrument. I don't want to throw it away because it still works, but fixing the lamp would cost more than buying a new one.
pantulis 2y ago
> "I’m quite impressed by how many independent mechanisms there are to prevent the magnetron from accidentally turning on. " Ok, I've never been really fond of microwave ovens so I don't use mine that much. After reading this I am starting to fear my microwave, definitely.
mark-r 2y ago
Interesting that he thinks the clock would be better with a 32kHz crystal than with monitoring the 60Hz power frequency. The power line frequency is very tightly regulated over the long term, and should have an overall better accuracy.
- cesarb 2y ago
  > The power line frequency is very tightly regulated over the long term, and should have an overall better accuracy. It depends on your country. I've heard of this being the case in Europe, but here in Brazil, as far as I could find there's no "long term regulation" of the power line frequency. Which makes sense to me; it means the power network operator doesn't have to artificially deviate from the correct power line frequency in an attempt to "compensate" for a past deviation.

Link seems dead. wayback version: https://web.archive.org/web/20240910031602/https://blog.stuffedcow.net/2024/06/microwave-failure-spontaneously-turns-on/ https://web.archive.org/web/20240910031602/https://blog.stuf...

ThePowerOfFuet 2y ago

Unreadable on mobile. :(

hulitu 2y ago

> Microwave Oven Failure: Spontaneously turned on by its LED display It is an engineering failure. The oven is not to blame. /s

MisterTea 2y ago

Notice that door switch middle is a crowbar[1] which is there to prevent the magnetron from powering on when all else fails (and there is a lot of interlocking). My friends parents had a microwave that kept dying so I opened it up and realized one of the three switches was a crowbar and it blew the fuse. I changed the fuse and it powered on again and ran for a few more days until it blew again. They decided it was unsafe and canned it. 1. https://en.wikipedia.org/wiki/Crowbar_(circuit) https://en.wikipedia.org/wiki/Crowbar_(circuit)

MarkusWandel 2y ago
Ironically the switches are cheap (from Ali Express anyway) and easy to replace and TMK virtually all microwaves use the same type. But yes, when you open the door, they do the following, in order: - open to send a "stop microwaving" signal to the controller - open to physically open the power circuit to the magnetron transformer - close to short out the power after the above relay (the crowbar part) The bottom two relays (in the list, not necessarily physical order) are independent of what the control board does. If due to mechanical slop, the bottom one switches before the middle one, boom goes the fuse. Even if you're just opening the door of an idle microwave. That's why, at least in mine, it says on a label inside, if the fuse is blown, replace the door switches along with the fuse. The sequencing is very tight. You have to push the button veeerrry slooowly to actually observe the switches clicking in sequence.

arghandugh 2y ago

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.

quesera 2y ago
That sounds dangerous, and deserving of a name & shame. Or a YouTube video with a pack of microwave popcorn that spontaneously pops and burns and smokes.
ak217 2y ago
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.
- arghandugh 2y ago
  Yep, the GE over-the-range model PNM9196SF3SS. GE is just a Haier badge since 2016. I'm not surprised by a Chinese company not giving a shit, but for a microwave magnetron to fire on its own feels like a sign of deep engineering rot. The only fix was to unplug it then swap the logic board. Once it happened again with the new board we threw it out.
  - xattt 2y ago
    I had non-stop issues with GE OTR microwaves for 2 years. I started with a PVM2188SLJC that I ended up getting replaced three times by GE over a year for separate issues (buzzing turntable, cracked casing). I ended spamming the executive team and got an upgraded model with convect for free. Fast forward two years later, and the fuse tripped inside the microwave after I forget a bottle sterilizer overnight, on Christmas Day. I said fuck this, and went and got a Panasonic NN-SG158. The twist was that it looked like it was a different version of the first GE microwave we had from the same OEM, but a little reworked.

r00fus 2y ago

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 microwave beeps only once after complete and it's not incredibly loud. Despite my kids literally abusing this device, it's been rock solid for 7+ years. Amusingly my company started putting these same exact models in our office break/kitchen areas a couple years after I bought mine. [1] https://www.amazon.com/gp/product/B00BDF5ZNS https://www.amazon.com/gp/product/B00BDF5ZNS

sonofhans 2y ago
Great minds think alike. That is exactly the microwave I have, and for the same reasons. Such a brilliant tool.
goda90 2y ago
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.
- apricot 2y ago
  The commercial microwaves we have at work have both a large dial to set the time, and four large buttons under it for 25%, 50%, 75% and 100% power. No other controls. They are great.
  - hammock 2y ago
    If the power level buttons were an old school radio button that would be so cool
    - 2y ago

sonofhans 2y ago

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 controls, rather than a myriad of popcorn/pizza/whatever buttons. Commercial microwaves often have an integrated diffuser, so they don’t need the stupid rotating glass plate in the bottom.

ToucanLoucan 2y ago
Can confirm. We got a commercial-grade Panasonic microwave I believe, that survived near daily use for almost 9 years before the magnetron finally gave out. We replaced it with an identical model, and it must be a pretty good one since a cursory comparison inside between the old and new revealed virtually no changes since our old one was made. If it ain't broke...
- MarkusWandel 2y ago
  Can confirm because at my work, they initially put ordinary consumer microwaves in at the coffee/lunch stations. They failed quickly. The commercial ones last. However the latest ones have a very flimsy feeling control wheel, I somehow imagine a 25 cent rotary encoder behind that which, if it fails, may still cause the otherwise solid machine to be discarded.
  - bzzzt 2y ago
    That's not all bad. Someone who can replace a 25 cent encoder can enjoy a lifetime of microwaving ;)
- ssl-3 2y ago
  I cooked for a family in part with a consumer-grade, Walmart-sourced Panasonic inverter microwave oven for a dozen years until circumstances made me get rid of (donate) it. No issues ever. It was reliable, had some useful programming options (that nobody ever used but me, but it had them), and it did a good job of microwaving food in a consistent and predictable manner. (But that's not an indication that inverters are reliable, or that consumer is the same as professional, or that Panasonic is good, or of anything else really other than that anecdotes are anecdotes.)

yborg 2y ago

My microwave is a 1993 Panasonic. It sat in a basement for about 10 of the intervening years, but has been a daily driver for the last 6-7. Comparing it to current retail units, it's remarkable how little has changed in that time.

deleted 2y ago

[deleted]

Retr0id 2y ago

I have a Samsung microwave with a really weird bug. If the door is just a few millimetres ajar, it turns on by itself. It's not just mine either, a lot of reviewers point out the same. It seems to be a design flaw. It's not a huge issue, since I'm not exactly in the habit of positioning the door in a half-open state. My guess is that they have some broken/inverted logic related to the "turn off if the door is open" feature.

solid_fuel 2y ago
I remember this flaw in a Samsung microwave from ~2007-2008. It freaked me out when I triggered it while trying to quietly close the door.
djmips 2y ago
The article describes such an issue but the assures that the oven magnetron doesn't run. Maybe it's a similar problem where the turntable and light come on in that situation.

ctrlGsysop 2y ago

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 and continue to run. Zero logic protection.

djmips 2y ago
They mention that in the article but assure that the magneton does not run.
- ctrlGsysop 2y ago
  Indeed, nothing is heating in this state.
BlueGh0st 2y ago
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.
farkanoid 2y ago
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 http://up.orificeworks.com/nn-cd997s_cd987w.pdf
xattt 2y ago
The magnetron is on an interlock that blows a fuse if the door microswitch is on.

omoikane 2y ago

One of the comments linked to an article about keyboard problems caused by a LED, which was previously discussed here: https://news.ycombinator.com/item?id=36581204 https://news.ycombinator.com/item?id=36581204 - Repair adventure: A single white LED causing stuck keys on a RN988 keyboard (2023-07-05) I wasn't thinking about the color of the LED at the time, but after reading this article, I wonder if we should prefer products with green LEDs in general, like green LEDs are just more reliable than blue/white LEDs for some reason? Also, I can't seem to find microwave ovens with red LEDs.

userbinator 2y ago

The title is a bit clickbaity, since the actual "oven" part (the magnetron) stayed off. As it should, since the safeties for it are much more robust than the other parts: I’m quite impressed by how many independent mechanisms there are to prevent the magnetron from accidentally turning on. Not only are there three door switches to ensure the door is closed, there’s also a mechanism to guard against a faulty microcontroller or software. Personally, I think the ones with mechnical controls, no microcontroller, are the most reliable and also easiest to repair.

rdtsc 2y ago

I scared myself with my microwave, a cheaper Samsung. Somehow it turned “itself” on when I opened the door once. I quickly slammed it shot and jumped back. Hopefully it’s this exact failure and the magnetron didn’t actually start.

dusted 2y ago

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.

bschwindHN 2y ago
You are exactly correct, and I'll die on that hill alongside you.
- kwhitefoot 2y ago
  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.
martin_a 2y ago
I'd be interested in such a simple device, but does anybody even produce tech _that simple_?
TimeBearingDown 2y ago
Don’t forget a physical handle to pull open the door. I’d take a steam sensor as well. Thanks to Technology Connections, great channel. Convinced me to read all the fine print until I found a Breville that had it. https://youtu.be/UiS27feX8o0 https://youtu.be/UiS27feX8o0
pphysch 2y ago
Simple is good but another approach to simplicity would be more sensors (weight, thermal, steam, optical?) and a single "cook" button (or a menu/dial with few different cook options, defrost, warm, hot). For casual use the UX is superior as it requires less micromanagement. Also lot more difficult to engineer well, though.

pajko 2y ago

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.

reconvene1290 2y ago

Must be one sexy LED display.

ajb 2y ago

Nice investigation! My 25 year old microwave is really solid, except for the lamp, which has blown. It's an old bulb so it should be replaceable - except that physically there's no way to do it without unscrewing the magnetron, which is well into scary territory - you need to basically re-qualify it after reassembly by scanning for leaks with a professional instrument. I don't want to throw it away because it still works, but fixing the lamp would cost more than buying a new one.

pantulis 2y ago

> "I’m quite impressed by how many independent mechanisms there are to prevent the magnetron from accidentally turning on. " Ok, I've never been really fond of microwave ovens so I don't use mine that much. After reading this I am starting to fear my microwave, definitely.

mark-r 2y ago

Interesting that he thinks the clock would be better with a 32kHz crystal than with monitoring the 60Hz power frequency. The power line frequency is very tightly regulated over the long term, and should have an overall better accuracy.

cesarb 2y ago
> The power line frequency is very tightly regulated over the long term, and should have an overall better accuracy. It depends on your country. I've heard of this being the case in Europe, but here in Brazil, as far as I could find there's no "long term regulation" of the power line frequency. Which makes sense to me; it means the power network operator doesn't have to artificially deviate from the correct power line frequency in an attempt to "compensate" for a past deviation.