11 ms·

We had a similar problem at work in the late 90s. A member of staff reported that their mouse would stop working between certain hours of the day. It had appare

We had a similar problem at work in the late 90s. A member of staff reported that their mouse would stop working between certain hours of the day. It had apparently been okay in the morning, stopped working over lunchtime then started again later. On some days it would work perfectly all day long, but on others it would stop working between those hours. The biggest clue was it would always work perfectly on overcast days, but on sunny days this strange behaviour would manifest again. Turns out the problem was related to the mouse being a cheap mouse. The case had very thin plastic. The mouse was a ball mouse, and it worked by shining an LED into a sensor on each of the X and Y axes. On sunny days the sun would completely overpower the sensor due to the plastic case being very thin and on overcast days it would not. On sunny days the mouse would only work when the sun had moved around the sky to cast a shadow over where the mouse was being used. Perfectly logical but baffling at first.

MalcolmDwyer 3y ago
We have a countertop ice maker that gets jammed up and overloaded with ice on sunny days for a similar reason. There's an infrared beam and sensor. When the ice tray is full, it is supposed to block the beam, and then the machine stops making ice. On a sunny day, there's enough bright light in our kitchen to fool the sensor so it keeps making ice. We have a random magazine that we put on top of it to make it work correctly.
- m463 3y ago
  I have a garage door that will not close on sunny days. Same sort of problem. The obstruction sensor at the bottom of the door is confused by the strong sunlight and the door stops closing part way and re-opens. I've tried a toilet-paper tube around the sensor but that isn't always successful. I really wish there was a laser sensor to replace it with.
  - kuroguro 3y ago
    The sad thing is there are certain IR wavelengths that are a lot less affected by the sun and nobody bothered to check for an outdoor product...
    - lotsofpulp 3y ago
      The garage door obstruction sensors are located inside the garage, so it technically might be an indoor product. Although, the possibility of a garage being oriented such that the sunlight would directly hit the sensors while the garage door is open seems like it could be a not infrequent occurrence.
  - djmips 3y ago
    Maybe experiment with filters. Also it could be 'fun' to swap out the LEDs?
  - sharadov 3y ago
    Similar problem toilet-paper hack worked.
  - giraffe333 3y ago
    I have this exact problem and (mostly) fixed it by swapping the sensor and transmitter. I just cut the wires and spliced with electrical tape. Now the problem still happens but only sometimes in the fall and spring when the sun's angle is just right. This is with a west facing garage about 41°N latitude USA. But yeah, why this isn't laser based, or using a light frequency that is less affected by sunlight? Probably cost, or ignorance.
    - dharmab 3y ago
      It varies by brand- some brands are better at filtering out sunlight than others. The home builder should know not to use certain brands in garages that face the sun... but they often don't. It'a not laser based so the sensors don't have to be perfectly aligned. Keeps your garage door working when you kid knocks it with their foot.
  - tbyehl 3y ago
    What sucks is those sensors are designed so you can't just jump a wire to permanently defeat them. You can, however, tape the sender and receiver together.
  - spoonjim 3y ago
    Very basic engineering would be to modulate the sender at a specific frequency
  - geocar 3y ago
    Paint your garage floor black: less light will reflect. It also is a lot easier to see fallen bolts and shit on a black floor than on a white/gray one.
  - dharmab 3y ago
    Is it a Genie system? My old Genie system had that exact same problem. Even making large sun shields out of Amazon boxes didn't fix it. I had to replace my opener and door anyway and had a conversation with a tech about it. We decided on a LiftMaster in part because their sensors are very good at dealing with sunlight.
  - rainbowzootsuit 3y ago
    Depending on the orientation of your garage door, exchanging the sensor could put it in an unaffected position. It looks like an industrial photoelectric sensor, including laser based ones run around $100, so maybe that can be a realistic swap. https://www.automationdirect.com/adc/shopping/catalog/sensors_-z-_encoders/photoelectric_sensors/general_purpose_photoelectric_sensors https://www.automationdirect.com/adc/shopping/catalog/sensor...
- 13of40 3y ago
  I had a VCR back in the day that refused to function if you opened its case. It turned out that instead of using physical switches inside it used pairs of lights and detectors that would give false positive results when ambient light shined on them.
  - aksss 3y ago
    as in an optocoupler? Those are the coolest, especially for dealing with different voltages.
    - alexdbird 3y ago
      No, there's not any call for high voltages in a VCR, outside the feedback loop of a SMPS if it's fancy. The most common thing to use light sensors is just detecting the difference between tape and clear leader at the ends of the tape (or broken tape).
asddubs 3y ago
Another similar anecdote I heard before was related to a wireless device, and some employees flying a drone during their break, generating interference.
- ethbr1 3y ago
  My parents have some old Gateway amplified computer speakers. Came with the 386! They still work perfectly... except for a regular pop of noise every few seconds that would intermittently show up, that scaled with the volume setting. It turned out, their portable phone (read: landline with short-distance wireless RF handset) would ping from the base station to the handset, if it were off the cradle, which was being picked up by the unshielded line-level audio cable and amplified. Moved the base station further from the cable, pop disappeared.
  - valbaca 3y ago
    Remember how old speakers would let you know if you were about to get a cellphone call. It was like digital precognition haha
    - genewitch 3y ago
      i found this and had to find this thread... https://www.youtube.com/shorts/Q-6M2P6mAx4 https://www.youtube.com/shorts/Q-6M2P6mAx4
    - genewitch 3y ago
      you can still hear cellphone and wifi noise in crappy amplifiers - i have two sets of active muff hearing protection - the ones with microphones on each earpiece, and if you get inbetween a beamforming WAP or near any wifi antenna, or near a cellphone, you get "brrz bz bz bz bzzzzzz tiktiktiktiktik". But this is different than the old <2g/edge phones, which wouldn't interfere unless you were about to get a call - because the tower said "where's this phone?" and your phone would max out it's tx and say "here i am!" and that's what you heard. This is probably incorrect, but based on my observations this is what occurred. Remember the doodads you could put on your startac style phones on the antenna bit, with LEDs in them - they'd light up when you were about to get a call, as well, by design!
98codes 3y ago
I had a similar problem, but in the opposite direction. My cable internet speeds at home were fairly good (for the US, anyway), but sometimes would absolutely bottom out. Not dead, just glacially slow. After troubleshooting everything under the sun, I came to realize that the problems would happen not when it was raining per se, but when it was heavily foggy or misting. Normal to heavy rain was fine. Called the cable company, tech came out. Everything inside was fine, but the cable from the main line to the house had a tiny cut in one spot, not enough to really affect the connection, but enough for ambient moisture to work its way in and foul the connection.
- deleted 3y ago
  [deleted]
- lostlogin 3y ago
  Moisture in copper cables is what slowed me down too. It was in a section up the road from me. However now that fibre is installed, it’s glorious and works in the rain.
- lxgr 3y ago
  Having had to debug many of such cable issues in the past, it's baffling to me that cable companies aren't proactively monitoring for things like this. They have all the data available on their end, as far as I can tell! (Unless DOCSIS modems somehow don't have a standard "signal receive report" functionality?)
  - Animats 3y ago
    Telcos used to monitor their copper outside plant for moisture. This was called Automatic Line Insulation Testing in the Bell System. The ALIT system ran in the hours before dawn. It would connect to each idle line, and apply, for tens of milliseconds, about 400 volts limited to very low current between the two wires, and between each wire and ground, measuring the leakage current. This would detect moisture in the cable. This was dealt with by hooking up a tank of dry nitrogen to the cable to dry it out. Here's a 1960s vintage Automatic Electric line insulation test system at work in a step-by-step central ofice. [1] Here's the manual for automatic line insulation testing in a 5ESS switch.[2] 5ESS is still the major AT&T switch for copper analog phone lines. After that, it's all packet switching. For fiber, of course, moisture doesn't affect the signal. This led to an urban legend: "bell tap". While Western Electric phones were designed to not react to the ALIT test signal, many cheap phones would emit some sound from the "ringer" when the 400V pulses came through, some time before dawn. [1] https://www.youtube.com/watch?v=Wt1GGdDa5jQ https://www.youtube.com/watch?v=Wt1GGdDa5jQ [2] https://www.manualslib.com/manual/2755956/Lucent-Technologies-5ess-2000.html?page=15 https://www.manualslib.com/manual/2755956/Lucent-Technologie...
kqbx 3y ago
Reminds me of a problem that I had (many years ago) with my iPhone 4 - if I tried to boot it in a dark place, it would get stuck on the Apple logo in an infinite boot loop. Turns out some versions of the Pangu jailbreak for iOS 7.1.x would crash during boot if the reading from the ambient light sensor was below some threshold. To this day I don't know the exact explanation of this bug, but it seems that Pangu included some unnecessary code that messed with the light sensor [1]. If you don't believe me, there is a huge reddit thread[2] with a lot of people confirming this. [1] https://www.reddit.com/r/jailbreak/comments/294wob/jailbreak_with_pangu_and_bootloop_try_this_fix_oo/cijfwh9 https://www.reddit.com/r/jailbreak/comments/294wob/jailbreak... [2] https://www.reddit.com/294wob/ https://www.reddit.com/294wob/
- andersrs 3y ago
  The intent might have been to prevent it turning on while in your pocket.
- womod 3y ago
  That's funny, there exists a similar issue with the LG G7 that a friend of mine ran into several years ago. The fingerprint sensor on his phone just straight-up completely stopped working, and subsequent OS updates did nothing to fix it. At first we assumed it was hardware failure, and he was ready to send it to a repair shop. While investigating it I saw a comment somewhere that it had something to do with the light sensor, and after holding my thumb over it for 10 seconds it "magically" started working again after 4 months of being completely non-functional.
- chronicsonic 3y ago
  Engineers love problem solving. I always see it as a challenge. No matter how unimportant.
- saagarjha 3y ago
  Seems unlikely. I don't have access to the paste but from the comment below it I think it's probably a false positive that Pangu was doing something with the sensor. (Not that I don't doubt that the sensor could be the problem, it's just that the code is not very conclusive.)
valbaca 3y ago
Had a similar effect with garage door sensors and TVs which use infrared. During sunset, the sun would line up juust right to blank out the sensors
jonhohle 3y ago
When it’s sunny, my wife’s car can’t open the garage door, and my car requires getting extremely close. Once the sun goes down, we can both open the door from the street. It turns out our solar panels (or the optimizers, or the inverter) emit radio frequencies that interfere with our garage door opener. When the sun is out and they are producing energy, the interference is stronger than the homelink garage door opener. A few years ago the garage door openers started working fine. It took a few days to realize it was because the inverter had failed. I’m fairly certain there are some FCC regulations that would require our installer to fix it, but that relationship soured during installation and I’d rather deal with an unusable garage remote than dealing with them for warranty work.
- djmips 3y ago
  Just curious but did you try any bodged shielding?
  - jonhohle 3y ago
    I used a coax cable to move the antenna closer to the exterior wall and didn’t see an improvement, however, I might not have grounded the shielding properly. I’ve had to replace the control board since then and didn’t replace the antenna on the new board, but may try that again.
- _whiteCaps_ 3y ago
  Some clip on ferrites on the inverter cables might help. If you have any amateur radio neighbours they'd probably love to help you with a project like this.
  - TeMPOraL 3y ago
    If they had a HAM in direct neighborhood, I imagine said HAM would already pay them a visit - the interference from the inverter is likely not constrained to the ISM band.
    - 3y ago
aidos 3y ago
This happened to me in my first job and it took me weeks to figure it out. The penny dropped and I put tape around the thin gap in the casing where the top joined to the bottom and it fixed it immediately.
kulahan 3y ago
I love these kinds of problems. There's an old story about a bug where some people couldn't send an email further than 500 miles. Huh? https://web.mit.edu/jemorris/humor/500-miles https://web.mit.edu/jemorris/humor/500-miles
- chrisbolt 3y ago
  Yesterday's discussion: https://news.ycombinator.com/item?id=37576633 https://news.ycombinator.com/item?id=37576633
geph2021 3y ago
reminds me of testing out a pinewood derby track in my backyard for our cub scouts pack. It had an IR sensor that would detect the cars at the finish line. When someone was standing next to the finish line, it worked flawlessly. Otherwise, it was very flaky and randomly would trigger without the cars trigger it. I pretty quickly surmised it was interference from the direct sunlight, so we put up a pop-up shade over it and it worked flawlessly (without someone standing nearby, coincidentally casting a shadow). The other dads were amazed that I figured it out, but it's just one of those things you learn from experience (and some background knowledge).
unsupp0rted 3y ago
I'm amazed an IT department would troubleshoot deeply enough to figure out it was the thin plastic letting in interfering light on sunny days. I would have guessed they'd shrug at the first sign of trouble, swap it out with a known-working mouse and mark the ticket resolved... unless all the replacement mice were thin plastic too, I suppose.
- doubled112 3y ago
  I can't leave something like that unexplained, and I've been an IT department before. It would bother me until I figured something out.
- repiret 3y ago
  Mice used to be expensive enough to troubleshoot.
  - unsupp0rted 3y ago
    For myself, I can't remember a time when a mouse cost more than an hour of an IT guy's time. I suppose a good office-computer mouse in 1990 would cost $100 ~ $200 (say $350 today). In that case, yes troubleshooting it for a day would make sense, especially if it's not an isolated problem.
    - thaumasiotes 3y ago
      > For myself, I can't remember a time when a mouse cost more than an hour of an IT guy's time. This is not a sensible comparison to make. Support staff have a lot of free time. They have to, because they're support staff -- if they were always busy, then whenever a problem arose, it would be impossible to get support. So to have the IT department playing with the mouse is unlikely to cost the company anything. If something comes in that's more important, the mouse problem will be put aside. If they have nothing better to do, they can play with the mouse.
- jacamera 3y ago
  I'm assuming it was a trackball mouse from the description. The OP said it was cheap so I don't think cost was an issue but from my experience some employees are very particular about their peripherals (don't blame them one bit!). If they're important enough (or maybe just nice enough) I could absolutely imagine spending the time to make sure their preferred device is working properly.
qingcharles 3y ago
Argh. My own mouse not working one: - Use to fix PCs professionally in the early 90s. - Guy comes in with PC. Right-mouse button stopped working. - Replace mouse. Still not working. - Play with Windows 3.1 drivers. Nothing helps. - Pull HDD from another PC, install, boot. Mouse button still broken. WTF. - Pull whole mobo, put another spare mobo in, with replacement HDD and replacement mouse. Still don't work. - Replace PSU. Right-button works. - Give up on computers, live in wilderness, eat squirrels.
- irrational 3y ago
  I used to know an older woman who did trap and eat squirrels as her main source of protein, so... this isn't entirely unlikely.
  - qup 3y ago
    What was her trap like?
nvy 3y ago
Your car repeatedly doesn't start so instead of taking it to the shop, you... write a letter to the CEO of Pontiac who not only actually reads the letter but also personally dispatches an engineer to waste a week going out for ice cream? And Pontiacs have a known vapor lock design flaw that only you, the letter writer, are experiencing? And you've only experienced it on your ice cream runs? And you've never got the vanilla ice cream but took a little extra long so the vapor lock dissipated and disproved your cute theory about vanilla ice cream? Seriously, this is one of those dumbass stories that come from your boomer relatives with the subject line "fwd: fwd: fwd: fwd: fwd: fwd: fwd: fwd: re: fwd: fwd: fwd: fwd: fwd: fwd: vanilla ice cream" Nobody actually believes this story is true, right?
- lamename 3y ago
  While I appreciate your point, I think anyone who has spent sufficient time troubleshooting complex systems has dealt with similar types of problems, and can grasp the _spirit_ of the story. In fact, I'd argue the quaint style of the story does geeks a favor: if it's appealing to normies, maybe they'll appreciate us technical folks' perspective a little more.
  - kawhah 3y ago
    actually the story is detrimental to helping people understand how technical systems and troubleshooting work, because it's so poorly invented. lots of people, both technical professionals, and non-engineers who are observant and have an appropriate level of belief in causality, troubleshoot transient failures like this all the time. a difference in the amount of time between shutting down the engine and starting it up is one of the first things that someone like this would test, or control for. it's beyond implausible that the second time the guy got vanilla (after riding along for 4 trips, two long and two short), the engineer didn't raise the question of how long he was in the store. people troubleshoot things like this by being able to separate causes which are plausible, although unlikely and surprising, from things which aren't remotely plausible. the 500-mile email story and the stories above about sunlight interfering with sensors demonstrate this. if you're the sort of person who believes that the type of ice cream you get might affecting your car's ignition - the type of person who buys ice cream often but never thinks about how long the errand takes, you simply never get the point of being able to make a pattern between those two things. the second time your car doesn't start, you blame it on the scratch-off lottery ticket you won $2 on which used up your supply of luck for the day. the third time, you conclude that the car ignition knew you were late and likes to choose its failures to cause maximum annoyance. and the fourth time, you realize that your mother-in-law gave your car the evil eye that morning. the story as told, especially when presented as a real parable about engineering rather than an amusing myth, is frankly insulting to the other type of person. the untrained, not necessarily educated person who cares about machines and believes in material reality. the person who starts checking their watch each time they go to the store and a couple of weeks later is telling their mechanic friend "if it's more than 3 minutes or so, it's fine. but if you try and start it before 2 minutes, then you have to wait another 5 before it's ready to go".
ssl-3 3y ago
I have a similar stories. The first was a VDSL connection I had at home. It worked great (fast, for the time) except when it didn't. It always failed in the evening. Techs would come out, bless it as being good, and leave -- because of course it worked while they were there. Unless they showed up and it was broken and then they'd declare that it was an outside problem, and that they'd have to get someone else to fix it (because the residential techs can't do overhead work). I made lots of (very polite) phone calls, which results in more refunds and more service calls. More than once, my driveway and the street in front of my house looked like an AT&T convention. This went on for months. I had direct numbers and emails for tier 3 support and the local manager who oversaw this plant. We were all getting to know eachother too well, and there were boots on the ground addressing this problem as many as three times in week. I eventually noticed that as the days got shorter so did the evening outages...and that if it was a cloudy day, then that day was often outage-free. I had an epiphany: The problem might correlate with the angle of the sun, and the duration of exposure! I checked my logs and the past weather, and sure enough: It lined up. So I reported my findings, even though they seemed like nonsense as the words came out of my mouth, and they sent out some crazy-haired guy with bluejeans and an untucked shirt who was clearly not used to wearing a uniform, and who was also obviously not normally customer-facing. "I know exactly why they can't find the problem," he said after I reiterated what I'd learned. "Your neighborhood still has old lead-sheathed overhead lines, and nobody knows how to work on that anymore." "But I'm certified on that. I'm going to go back to the shop, pick up a bucket truck and get your line fixed. It will take me most of a day to do this, but I will be back when I'm done." And it was getting pretty late, but he did come back to let me know that he found some things and fixed them. And I don't know what those things were, but it was fine after that -- and it stayed fine. Thermal expansion letting cosmic rays leak into copper pairs wrapped in paper, tar, and lead? Who knows. I certainly don't know. I've never encountered that stuff professionally (and it isn't your grandfather's 25-pair cable) and as this dude said, "nobody knows how to work on that anymore."
mlegendre 3y ago
Your mouse story makes me think of the day the CI system at work turned out not to be robust to vibrations. One day we started having flaky tests, seemingly out of nowhere. We quickly identified that the issue affected tests involving graphical X client applications, but then we struggled to make further progress. The issue was just impossible to reproduce in other conditions... Well, as it happens, the CI jobs were running on some desktop machines we had installed somewhere within our premises. It turned out that some gentleman had plugged a mouse into one of the machines, and left it lying around on the shelf. Since then, when one of the machines was under a heavy load, the fans would spin faster, causing more vibrations, in turn causing the mouse to move, ever so slightly. And for ungodly reasons, this had side effects on tests. Fun fact: the machines were not on my site, I managed to diagnose this over SSH. I was quite proud :-)
- dharmab 3y ago
  > And for ungodly reasons, this had side effects on tests. Let me guess - tests with very tight timings?
  - mlegendre 3y ago
    Sadly I can't remember this part; I'm pretty sure there were comical bits to it. This makes me want to dig out the gitlab issue, and turn it into a better write-up! This'll have to wait until I'm back from holidays though.
janxgeist 3y ago
We had a similiar problem with a label printer. On some days, exclusively in the morning hours, the printer would fail to detect the start of a new label, printing over several labels. After connecting remotely and checking the usual (queue, network connection, drivers etc), I asked my colleague to call me, as soon as it happened again. When I went there, I saw that a ray of sunlight hit the printer. The windows had shutters, but there was a gap. Label printers detect the gap between labels using a laser. And for some reason, the printer's case had a clear window at the top. I printed an empty label and stuck it on the little window.
- Paul-Craft 3y ago
  Printer, fix thyself!

MalcolmDwyer 3y ago

We have a countertop ice maker that gets jammed up and overloaded with ice on sunny days for a similar reason. There's an infrared beam and sensor. When the ice tray is full, it is supposed to block the beam, and then the machine stops making ice. On a sunny day, there's enough bright light in our kitchen to fool the sensor so it keeps making ice. We have a random magazine that we put on top of it to make it work correctly.

m463 3y ago
I have a garage door that will not close on sunny days. Same sort of problem. The obstruction sensor at the bottom of the door is confused by the strong sunlight and the door stops closing part way and re-opens. I've tried a toilet-paper tube around the sensor but that isn't always successful. I really wish there was a laser sensor to replace it with.
- kuroguro 3y ago
  The sad thing is there are certain IR wavelengths that are a lot less affected by the sun and nobody bothered to check for an outdoor product...
  - lotsofpulp 3y ago
    The garage door obstruction sensors are located inside the garage, so it technically might be an indoor product. Although, the possibility of a garage being oriented such that the sunlight would directly hit the sensors while the garage door is open seems like it could be a not infrequent occurrence.
- djmips 3y ago
  Maybe experiment with filters. Also it could be 'fun' to swap out the LEDs?
- sharadov 3y ago
  Similar problem toilet-paper hack worked.
- giraffe333 3y ago
  I have this exact problem and (mostly) fixed it by swapping the sensor and transmitter. I just cut the wires and spliced with electrical tape. Now the problem still happens but only sometimes in the fall and spring when the sun's angle is just right. This is with a west facing garage about 41°N latitude USA. But yeah, why this isn't laser based, or using a light frequency that is less affected by sunlight? Probably cost, or ignorance.
  - dharmab 3y ago
    It varies by brand- some brands are better at filtering out sunlight than others. The home builder should know not to use certain brands in garages that face the sun... but they often don't. It'a not laser based so the sensors don't have to be perfectly aligned. Keeps your garage door working when you kid knocks it with their foot.
- tbyehl 3y ago
  What sucks is those sensors are designed so you can't just jump a wire to permanently defeat them. You can, however, tape the sender and receiver together.
- spoonjim 3y ago
  Very basic engineering would be to modulate the sender at a specific frequency
- geocar 3y ago
  Paint your garage floor black: less light will reflect. It also is a lot easier to see fallen bolts and shit on a black floor than on a white/gray one.
- dharmab 3y ago
  Is it a Genie system? My old Genie system had that exact same problem. Even making large sun shields out of Amazon boxes didn't fix it. I had to replace my opener and door anyway and had a conversation with a tech about it. We decided on a LiftMaster in part because their sensors are very good at dealing with sunlight.
- rainbowzootsuit 3y ago
  Depending on the orientation of your garage door, exchanging the sensor could put it in an unaffected position. It looks like an industrial photoelectric sensor, including laser based ones run around $100, so maybe that can be a realistic swap. https://www.automationdirect.com/adc/shopping/catalog/sensors_-z-_encoders/photoelectric_sensors/general_purpose_photoelectric_sensors https://www.automationdirect.com/adc/shopping/catalog/sensor...
13of40 3y ago
I had a VCR back in the day that refused to function if you opened its case. It turned out that instead of using physical switches inside it used pairs of lights and detectors that would give false positive results when ambient light shined on them.
- aksss 3y ago
  as in an optocoupler? Those are the coolest, especially for dealing with different voltages.
  - alexdbird 3y ago
    No, there's not any call for high voltages in a VCR, outside the feedback loop of a SMPS if it's fancy. The most common thing to use light sensors is just detecting the difference between tape and clear leader at the ends of the tape (or broken tape).

asddubs 3y ago

Another similar anecdote I heard before was related to a wireless device, and some employees flying a drone during their break, generating interference.

ethbr1 3y ago
My parents have some old Gateway amplified computer speakers. Came with the 386! They still work perfectly... except for a regular pop of noise every few seconds that would intermittently show up, that scaled with the volume setting. It turned out, their portable phone (read: landline with short-distance wireless RF handset) would ping from the base station to the handset, if it were off the cradle, which was being picked up by the unshielded line-level audio cable and amplified. Moved the base station further from the cable, pop disappeared.
- valbaca 3y ago
  Remember how old speakers would let you know if you were about to get a cellphone call. It was like digital precognition haha
  - genewitch 3y ago
    i found this and had to find this thread... https://www.youtube.com/shorts/Q-6M2P6mAx4 https://www.youtube.com/shorts/Q-6M2P6mAx4
  - genewitch 3y ago
    you can still hear cellphone and wifi noise in crappy amplifiers - i have two sets of active muff hearing protection - the ones with microphones on each earpiece, and if you get inbetween a beamforming WAP or near any wifi antenna, or near a cellphone, you get "brrz bz bz bz bzzzzzz tiktiktiktiktik". But this is different than the old <2g/edge phones, which wouldn't interfere unless you were about to get a call - because the tower said "where's this phone?" and your phone would max out it's tx and say "here i am!" and that's what you heard. This is probably incorrect, but based on my observations this is what occurred. Remember the doodads you could put on your startac style phones on the antenna bit, with LEDs in them - they'd light up when you were about to get a call, as well, by design!

98codes 3y ago

I had a similar problem, but in the opposite direction. My cable internet speeds at home were fairly good (for the US, anyway), but sometimes would absolutely bottom out. Not dead, just glacially slow. After troubleshooting everything under the sun, I came to realize that the problems would happen not when it was raining per se, but when it was heavily foggy or misting. Normal to heavy rain was fine. Called the cable company, tech came out. Everything inside was fine, but the cable from the main line to the house had a tiny cut in one spot, not enough to really affect the connection, but enough for ambient moisture to work its way in and foul the connection.

deleted 3y ago
[deleted]
lostlogin 3y ago
Moisture in copper cables is what slowed me down too. It was in a section up the road from me. However now that fibre is installed, it’s glorious and works in the rain.
lxgr 3y ago
Having had to debug many of such cable issues in the past, it's baffling to me that cable companies aren't proactively monitoring for things like this. They have all the data available on their end, as far as I can tell! (Unless DOCSIS modems somehow don't have a standard "signal receive report" functionality?)
- Animats 3y ago
  Telcos used to monitor their copper outside plant for moisture. This was called Automatic Line Insulation Testing in the Bell System. The ALIT system ran in the hours before dawn. It would connect to each idle line, and apply, for tens of milliseconds, about 400 volts limited to very low current between the two wires, and between each wire and ground, measuring the leakage current. This would detect moisture in the cable. This was dealt with by hooking up a tank of dry nitrogen to the cable to dry it out. Here's a 1960s vintage Automatic Electric line insulation test system at work in a step-by-step central ofice. [1] Here's the manual for automatic line insulation testing in a 5ESS switch.[2] 5ESS is still the major AT&T switch for copper analog phone lines. After that, it's all packet switching. For fiber, of course, moisture doesn't affect the signal. This led to an urban legend: "bell tap". While Western Electric phones were designed to not react to the ALIT test signal, many cheap phones would emit some sound from the "ringer" when the 400V pulses came through, some time before dawn. [1] https://www.youtube.com/watch?v=Wt1GGdDa5jQ https://www.youtube.com/watch?v=Wt1GGdDa5jQ [2] https://www.manualslib.com/manual/2755956/Lucent-Technologies-5ess-2000.html?page=15 https://www.manualslib.com/manual/2755956/Lucent-Technologie...

kqbx 3y ago

Reminds me of a problem that I had (many years ago) with my iPhone 4 - if I tried to boot it in a dark place, it would get stuck on the Apple logo in an infinite boot loop. Turns out some versions of the Pangu jailbreak for iOS 7.1.x would crash during boot if the reading from the ambient light sensor was below some threshold. To this day I don't know the exact explanation of this bug, but it seems that Pangu included some unnecessary code that messed with the light sensor [1]. If you don't believe me, there is a huge reddit thread[2] with a lot of people confirming this. [1] https://www.reddit.com/r/jailbreak/comments/294wob/jailbreak_with_pangu_and_bootloop_try_this_fix_oo/cijfwh9 https://www.reddit.com/r/jailbreak/comments/294wob/jailbreak... [2] https://www.reddit.com/294wob/ https://www.reddit.com/294wob/

andersrs 3y ago
The intent might have been to prevent it turning on while in your pocket.
womod 3y ago
That's funny, there exists a similar issue with the LG G7 that a friend of mine ran into several years ago. The fingerprint sensor on his phone just straight-up completely stopped working, and subsequent OS updates did nothing to fix it. At first we assumed it was hardware failure, and he was ready to send it to a repair shop. While investigating it I saw a comment somewhere that it had something to do with the light sensor, and after holding my thumb over it for 10 seconds it "magically" started working again after 4 months of being completely non-functional.
chronicsonic 3y ago
Engineers love problem solving. I always see it as a challenge. No matter how unimportant.
saagarjha 3y ago
Seems unlikely. I don't have access to the paste but from the comment below it I think it's probably a false positive that Pangu was doing something with the sensor. (Not that I don't doubt that the sensor could be the problem, it's just that the code is not very conclusive.)

valbaca 3y ago

Had a similar effect with garage door sensors and TVs which use infrared. During sunset, the sun would line up juust right to blank out the sensors

jonhohle 3y ago

When it’s sunny, my wife’s car can’t open the garage door, and my car requires getting extremely close. Once the sun goes down, we can both open the door from the street. It turns out our solar panels (or the optimizers, or the inverter) emit radio frequencies that interfere with our garage door opener. When the sun is out and they are producing energy, the interference is stronger than the homelink garage door opener. A few years ago the garage door openers started working fine. It took a few days to realize it was because the inverter had failed. I’m fairly certain there are some FCC regulations that would require our installer to fix it, but that relationship soured during installation and I’d rather deal with an unusable garage remote than dealing with them for warranty work.

djmips 3y ago
Just curious but did you try any bodged shielding?
- jonhohle 3y ago
  I used a coax cable to move the antenna closer to the exterior wall and didn’t see an improvement, however, I might not have grounded the shielding properly. I’ve had to replace the control board since then and didn’t replace the antenna on the new board, but may try that again.
_whiteCaps_ 3y ago
Some clip on ferrites on the inverter cables might help. If you have any amateur radio neighbours they'd probably love to help you with a project like this.
- TeMPOraL 3y ago
  If they had a HAM in direct neighborhood, I imagine said HAM would already pay them a visit - the interference from the inverter is likely not constrained to the ISM band.
  - 3y ago

aidos 3y ago

This happened to me in my first job and it took me weeks to figure it out. The penny dropped and I put tape around the thin gap in the casing where the top joined to the bottom and it fixed it immediately.

kulahan 3y ago

I love these kinds of problems. There's an old story about a bug where some people couldn't send an email further than 500 miles. Huh? https://web.mit.edu/jemorris/humor/500-miles https://web.mit.edu/jemorris/humor/500-miles

chrisbolt 3y ago
Yesterday's discussion: https://news.ycombinator.com/item?id=37576633 https://news.ycombinator.com/item?id=37576633

geph2021 3y ago

reminds me of testing out a pinewood derby track in my backyard for our cub scouts pack. It had an IR sensor that would detect the cars at the finish line. When someone was standing next to the finish line, it worked flawlessly. Otherwise, it was very flaky and randomly would trigger without the cars trigger it. I pretty quickly surmised it was interference from the direct sunlight, so we put up a pop-up shade over it and it worked flawlessly (without someone standing nearby, coincidentally casting a shadow). The other dads were amazed that I figured it out, but it's just one of those things you learn from experience (and some background knowledge).

unsupp0rted 3y ago

I'm amazed an IT department would troubleshoot deeply enough to figure out it was the thin plastic letting in interfering light on sunny days. I would have guessed they'd shrug at the first sign of trouble, swap it out with a known-working mouse and mark the ticket resolved... unless all the replacement mice were thin plastic too, I suppose.

doubled112 3y ago
I can't leave something like that unexplained, and I've been an IT department before. It would bother me until I figured something out.
repiret 3y ago
Mice used to be expensive enough to troubleshoot.
- unsupp0rted 3y ago
  For myself, I can't remember a time when a mouse cost more than an hour of an IT guy's time. I suppose a good office-computer mouse in 1990 would cost $100 ~ $200 (say $350 today). In that case, yes troubleshooting it for a day would make sense, especially if it's not an isolated problem.
  - thaumasiotes 3y ago
    > For myself, I can't remember a time when a mouse cost more than an hour of an IT guy's time. This is not a sensible comparison to make. Support staff have a lot of free time. They have to, because they're support staff -- if they were always busy, then whenever a problem arose, it would be impossible to get support. So to have the IT department playing with the mouse is unlikely to cost the company anything. If something comes in that's more important, the mouse problem will be put aside. If they have nothing better to do, they can play with the mouse.
jacamera 3y ago
I'm assuming it was a trackball mouse from the description. The OP said it was cheap so I don't think cost was an issue but from my experience some employees are very particular about their peripherals (don't blame them one bit!). If they're important enough (or maybe just nice enough) I could absolutely imagine spending the time to make sure their preferred device is working properly.

qingcharles 3y ago

Argh. My own mouse not working one: - Use to fix PCs professionally in the early 90s. - Guy comes in with PC. Right-mouse button stopped working. - Replace mouse. Still not working. - Play with Windows 3.1 drivers. Nothing helps. - Pull HDD from another PC, install, boot. Mouse button still broken. WTF. - Pull whole mobo, put another spare mobo in, with replacement HDD and replacement mouse. Still don't work. - Replace PSU. Right-button works. - Give up on computers, live in wilderness, eat squirrels.

irrational 3y ago
I used to know an older woman who did trap and eat squirrels as her main source of protein, so... this isn't entirely unlikely.
- qup 3y ago
  What was her trap like?

nvy 3y ago

Your car repeatedly doesn't start so instead of taking it to the shop, you... write a letter to the CEO of Pontiac who not only actually reads the letter but also personally dispatches an engineer to waste a week going out for ice cream? And Pontiacs have a known vapor lock design flaw that only you, the letter writer, are experiencing? And you've only experienced it on your ice cream runs? And you've never got the vanilla ice cream but took a little extra long so the vapor lock dissipated and disproved your cute theory about vanilla ice cream? Seriously, this is one of those dumbass stories that come from your boomer relatives with the subject line "fwd: fwd: fwd: fwd: fwd: fwd: fwd: fwd: re: fwd: fwd: fwd: fwd: fwd: fwd: vanilla ice cream" Nobody actually believes this story is true, right?

lamename 3y ago
While I appreciate your point, I think anyone who has spent sufficient time troubleshooting complex systems has dealt with similar types of problems, and can grasp the _spirit_ of the story. In fact, I'd argue the quaint style of the story does geeks a favor: if it's appealing to normies, maybe they'll appreciate us technical folks' perspective a little more.
- kawhah 3y ago
  actually the story is detrimental to helping people understand how technical systems and troubleshooting work, because it's so poorly invented. lots of people, both technical professionals, and non-engineers who are observant and have an appropriate level of belief in causality, troubleshoot transient failures like this all the time. a difference in the amount of time between shutting down the engine and starting it up is one of the first things that someone like this would test, or control for. it's beyond implausible that the second time the guy got vanilla (after riding along for 4 trips, two long and two short), the engineer didn't raise the question of how long he was in the store. people troubleshoot things like this by being able to separate causes which are plausible, although unlikely and surprising, from things which aren't remotely plausible. the 500-mile email story and the stories above about sunlight interfering with sensors demonstrate this. if you're the sort of person who believes that the type of ice cream you get might affecting your car's ignition - the type of person who buys ice cream often but never thinks about how long the errand takes, you simply never get the point of being able to make a pattern between those two things. the second time your car doesn't start, you blame it on the scratch-off lottery ticket you won $2 on which used up your supply of luck for the day. the third time, you conclude that the car ignition knew you were late and likes to choose its failures to cause maximum annoyance. and the fourth time, you realize that your mother-in-law gave your car the evil eye that morning. the story as told, especially when presented as a real parable about engineering rather than an amusing myth, is frankly insulting to the other type of person. the untrained, not necessarily educated person who cares about machines and believes in material reality. the person who starts checking their watch each time they go to the store and a couple of weeks later is telling their mechanic friend "if it's more than 3 minutes or so, it's fine. but if you try and start it before 2 minutes, then you have to wait another 5 before it's ready to go".

ssl-3 3y ago

I have a similar stories. The first was a VDSL connection I had at home. It worked great (fast, for the time) except when it didn't. It always failed in the evening. Techs would come out, bless it as being good, and leave -- because of course it worked while they were there. Unless they showed up and it was broken and then they'd declare that it was an outside problem, and that they'd have to get someone else to fix it (because the residential techs can't do overhead work). I made lots of (very polite) phone calls, which results in more refunds and more service calls. More than once, my driveway and the street in front of my house looked like an AT&T convention. This went on for months. I had direct numbers and emails for tier 3 support and the local manager who oversaw this plant. We were all getting to know eachother too well, and there were boots on the ground addressing this problem as many as three times in week. I eventually noticed that as the days got shorter so did the evening outages...and that if it was a cloudy day, then that day was often outage-free. I had an epiphany: The problem might correlate with the angle of the sun, and the duration of exposure! I checked my logs and the past weather, and sure enough: It lined up. So I reported my findings, even though they seemed like nonsense as the words came out of my mouth, and they sent out some crazy-haired guy with bluejeans and an untucked shirt who was clearly not used to wearing a uniform, and who was also obviously not normally customer-facing. "I know exactly why they can't find the problem," he said after I reiterated what I'd learned. "Your neighborhood still has old lead-sheathed overhead lines, and nobody knows how to work on that anymore." "But I'm certified on that. I'm going to go back to the shop, pick up a bucket truck and get your line fixed. It will take me most of a day to do this, but I will be back when I'm done." And it was getting pretty late, but he did come back to let me know that he found some things and fixed them. And I don't know what those things were, but it was fine after that -- and it stayed fine. Thermal expansion letting cosmic rays leak into copper pairs wrapped in paper, tar, and lead? Who knows. I certainly don't know. I've never encountered that stuff professionally (and it isn't your grandfather's 25-pair cable) and as this dude said, "nobody knows how to work on that anymore."

mlegendre 3y ago

Your mouse story makes me think of the day the CI system at work turned out not to be robust to vibrations. One day we started having flaky tests, seemingly out of nowhere. We quickly identified that the issue affected tests involving graphical X client applications, but then we struggled to make further progress. The issue was just impossible to reproduce in other conditions... Well, as it happens, the CI jobs were running on some desktop machines we had installed somewhere within our premises. It turned out that some gentleman had plugged a mouse into one of the machines, and left it lying around on the shelf. Since then, when one of the machines was under a heavy load, the fans would spin faster, causing more vibrations, in turn causing the mouse to move, ever so slightly. And for ungodly reasons, this had side effects on tests. Fun fact: the machines were not on my site, I managed to diagnose this over SSH. I was quite proud :-)

dharmab 3y ago
> And for ungodly reasons, this had side effects on tests. Let me guess - tests with very tight timings?
- mlegendre 3y ago
  Sadly I can't remember this part; I'm pretty sure there were comical bits to it. This makes me want to dig out the gitlab issue, and turn it into a better write-up! This'll have to wait until I'm back from holidays though.

janxgeist 3y ago

We had a similiar problem with a label printer. On some days, exclusively in the morning hours, the printer would fail to detect the start of a new label, printing over several labels. After connecting remotely and checking the usual (queue, network connection, drivers etc), I asked my colleague to call me, as soon as it happened again. When I went there, I saw that a ray of sunlight hit the printer. The windows had shutters, but there was a gap. Label printers detect the gap between labels using a laser. And for some reason, the printer's case had a clear window at the top. I printed an empty label and stuck it on the little window.

Paul-Craft 3y ago
Printer, fix thyself!