I was an admin for a company that had lots of open plan offices. In one of these offices a specific row of computers kept failing. Although they were cheap (Compaq Evos with NT4), they were pretty damn reliable throughout the rest of the company.

Lot of head scratching ensued about the fault. Nothing really made sense.

Totally by chance we found out what was wrong. One Saturday when the office was empty and with no a/c background noise one of the other admins noticed the PCs in the problem row weren't making any fan noise. A quick investigation revealed that the PSU fans had been blocked with paperclips and bits of paper causing the CPU to overheat.

An older member of staff who was in that row found the PSU fan noise irritating and just decided to take action to stop it. She genuinely didn't realise she was breaking the PCs.

I had a similar story. I set up a home pc for recording tv and hooked it up to the main entertainment system. I built it on a budget so it did it’s job but later on as we switched to more HD content it struggled occasionally.

I went off to college. My mom noticed the fan noise was increasing and found it distracting. She wrapped the pc in a couple of blankets to cut down on the noise. When I came home the thing was in danger of burning down the house and the video card had failed.

I am not sure if the following is true or one of those stories that gets recycled.

While I was working at Best Buy - the Geek squad told us a story of an older Lady who brought in a computer wrapped entirety in plastic saran wrap, to prevent the virus from escaping the computer and infecting people. She thought it was okay as she containing the virus and continued to use the computer before it turned off and didn't turn on again, which is whys she brought it in.

Oh, never underestimate people.

On the Pentium Overdrive! days, a guy came to my father's shop complaining that the computer wouldn't turn on. Turns out that he had installed the process in a different orientation "to see if it would go faster". Spoiler alert: it didn't.

Neither the CPU nor the motherboard failed (nor did the fancy overdrive socket). Once the CPU was installed correctly, it worked again.

My 'best' related Best Buy story (well, Future Shop a decade ago, but it is/was the same company) while working in the ConnectPro department (name for Geek Squad at Future Shop, all the same tools and procedures):

A person who had purchased a laptop a few hours prior came back into the store furious because the device shut off and wouldn't turn back on. I pressed the power button and it flashed indicating the battery was dead. I connected the laptop to power and told her it needed to be charged. She then threw a retail tantrum because the salesman had apparently told her it was wireless.

I think this really says more about a lack of basic science education in high school. People plug 1800W space heaters into $4 power strips and cause fires. I think by the time you graduate you should at least be able to understand that watts of electricity are the same thing as heat.

I had a similar mystery, except it was like every 5th or 6th cube and only happened in the winter. Turned out there were floor mounted heating ducts, and certain cubes were placed just right so that the hot air went directly into the PSU.

Some combo of heat, dust, and static caused gunk to accumulate in the fans, and eventually either the PSU or video card would overheat. The escalation usually came in that the monitor was tinted blue or pink.

I must confess that the eleven year old me didn't realize it would be a problem to put a screwdriver through the PSU grid to stop the fan from making noise and that it may have been preventing that musheen from working properly at some point.

Yeah, I am sensible to some sound :/.

The eleven years old me was doing the contrary: starting a crappy/sticky PSU fan with a screwdriver not realizing there was a "slight" risk of electrocution (never got a chock however, I guess I was somewhat aware of the danger).

I'm guilty of this at 14; this was the only way I could get away with late night BBSing since the fan was loud and other folks would be disrupted into halting my modem joy. Only when our EE neighbor saw my rig and sternly told me not to do that did I realize it meant anything at all. sheesh

I had a failing PSU that would shut down after an hour of intensive load. I booked it for RMA and was already packing the thing, when I noticed that a stray piece of plastic was stuck in the fan grill, blocking it. Worked fine ever since.

I've seen a similar accidental case where some internal cable in the PSU had gotten dislodged and was partially in the path of the fan blades, with the repeated contact making a chainsaw-like noise. Luckily it was discovered before the fan cut through the casing on the wire.

Hah, I had a SATA cable jammed into one of my GPU fans. I cursed Sapphire for building such a poor card that failed out of the box.

If you'd kept asking the 5 whys you'd have gotten to the real problem: noisy machines in open offices. You should have thanked the lady who put the paperclips on the fans.

That office was brutally loud. 100 people in a low ceiling office. The a/c was bad, but the plotters the engineering guys used were particularly brutal.

We also had dot matrix printers churning out triplicate documents.

They were lucky, us in IT were technically working illegally due to the noise in our part of the building. So many fans in so many server racks. Plus super cold a/c.

Out of curiosity, what happened to her ?

Nothing. Head if IT had words with her and she acknowledged What she did.

HR also offered her a free hearing assesment. It was a semi-state co so they actually cared for their staff.

> offered her a free hearing assesment

Hmm, doesn't sound like she needed it. Maybe only to figure out if her hearing was better than normal.

Here is a similar story from the childhood of computers: One of the first computers installed in a Norwegian university was of course in high demand, and students generally had to stay up at night to be able to use it. One morning, around 3 o'clock, the line printer came to a a halt and locked up the computer. They tried everything they could think of to get it going again, to no avail.

In the end they called the person in charge of the computer. He came over and closed the curtains, and the printer started up again. He left without a word of explanation.

That explanation emerged later: The early morning sun (the sun rises early in the summer here) was shining in, through the paper in the printer, onto the out-of-paper sensor, making the printer think it had no paper. Closing the curtain fixed it.

The word you are looking for is azimuth. The azimuth of the sun to the earth shifts as the earth wobbles throughout the year, and as we shift our time for daylights savings.

My garage door was affected by this until I created blinders for the trip sensor.. IR from the sun would cause the garage door to stay open. Lately I just watch my new neighbors leave their garage door open because they can’t figure out why

That is absolutely hilarious. Flashback to a similar technology `sleight of hand` -

Back in middleschool, when JavaScript's window.open allowed you easily to launch a fullscreen window with no browser chrome, and setting the background-image to a screenshot of the desktop... it was so entertaining watching students and teachers alike try to use the machine and thinking it was frozen!

My favorite version of this:

- screenshot someone's desktop

- set the background to the screenshot

- iconify all the apps

They'll click around in increasing panic on the "apps" on the background, before they realize what happened :)

Not that this ever happened to me, of course. I'd never fall for it again.

Tape on the bottom of the mouse is another common joke these days.

If the OS you are using has a taskbar, also set it to auto-hide, preferably in a random location.

As always, that kind of elaborate joke is best kept short. I also like replacing someone's shell with `wine cmd`, but nowadays the best protection for myself is that nobody seems to be able to use my computer (sway, full of shortcuts that you have to know in order to do anything). I'm similarly dumbfounded when at my friend's computers. Luckily, this is all fixed by opening a good old POSIX-compliant shell :)

Tape on the bottom of an Ethernet cable will guarantee a day of no work

And tech people wonder why the general populace doesn't like them.

We work hard for the pitchforks and torches..

In college, during the time I worked at the campus library in Stack Maintenance, on some days I also worked in the library computer lab. A joke we played on one friend was to take a screenshot of the regular computer desktop and make that the startup screen.

And the background screen.

And then use ResEdit to allow us to hide all the rest of the regular UI elements unless you typed the magic keyboard combination to un-hide them.

But that was a joke we played on a single friend. We knew that our friend could take a joke, and he wouldn't try to take revenge against us, or anything. No way we would do that on the general public.

Similar story in the USAF. We transitioned the academy from Banyon Vines to TCP/IP. An entire building wing went offline every day. A team was flown out with a network analyzer. Sure enough, same time every day, the entire wing of the building went offline. Turns out, the person buffing the floor needed a place to plug in the buffer and the only place they could find had this big box with lots of blinky LED's on it, so they unplugged it, buffed the floor and plugged it back in. Half-split troubleshooting may have saved a plane flight.

This is an old one. https://www.snopes.com/fact-check/polished-off/

The hospital story for sure, they have alarms on patient devices and battery backup for some, but I was there for the mmac-8 being unplugged.

The best part of this anecdote is that you mentioned Banyan Vines. Spent a handful of years installing/maintaining Banyan Vines network in the early 90's.

Amazing, and exact version of this happened to me in the Israeli Army in the 90's.

Every day at around 13:30 (give and take a few minutes) the network for an entire building went offline, only to come back on line a few minutes later.

... In our version of this 'bug' - one of the NCOs unplugged the electricity to that "big box with lots of blinky LEDs" in order to plugin an electric pot, to prepare his post-meal Turkish coffee, then plug it back in once water boiled...

Many resources were "thrown" at the problem, until, weeks in, someone had the splendid idea of quietly sitting around the network-cabinet around 13:30 and see what's going on.

I did an industrial automation class in college. We had a PLC setup with optical sensors and were sorting cylinders by height.

We wired it up tested it, then called the TA over to review. It failed despite no changes and working minutes earlier.

We changed some logic, tested again, and again called the TA over. It failed. We had another team look at our code and see if we were missing something obvious. Nope, it looked the same.

Finally I realized I was standing when we did the testing. I shaded the sensors and kept them from being overloaded with sunlight. We were the only table in direct sunlight, so only we were experiencing the issue.

Back in college (90's) we had a professor who, about once a year, would send an email to help desk saying his monitor had gotten blurry and he needed a new one. We'd go to his office, wipe off the thick layer of dust and it'd be as good as new again.

Did you try showing him the issue and how to handle it on his own?

How funny - exactly the same thing happened to me, which I wrote about in my first comment on HN: https://news.ycombinator.com/item?id=12482834

I had this one as "weird random stuff that no-one else will never get" so pleasing to know others - like you - not only hit the issue but also worked it out.

This reminds me of a similar issue I've experienced. A colleague always put his jacket onto his chair. Almost every time he took it off, his monitor connection broke for a few seconds. This mystery was never fully solved, but our best guess was some static (from the jacket-chair-friction) causing issues with his VGA-HDMI adapter.

I have this occasionally from my MacBook Pro to external 4k. My office seems to be conducive to generating static and I'll occasionally shock my MacBook when first sitting down, temporarily fritz-ing the connection to the monitor.

Remember exactly same thing happening to me some 18-19 years ago lol! It was in the time when mice still had balls, so the reading sensor got blinded by sunlight in at least one direction - sometimes mouse won't work at all, sometimes would but only on X or only on Y axis. Fix: install window shutters.

> ...It was in the time when mice still had balls,

Thinking of present times and times forgone: now mice lost not only balls, they lost their tails, and often find themselves devoid of any 3-dimensionality, being reduced to flat touchpads.

Using a mouse always felt to me as having a friedly handshake with the computer, something that touchpads can't emulate.

So... This would not happen with Linux?

I wonder if the downvoters missed the joke?

>Fix: install window shutters.

That's about the right timescale, I guess mice of the era was a bit 'sensitive'. Lucky we were a small office, I wouldn't have wanted to sent out a memo telling people to cover their mouse in the afternoon.

I work at a K-12 school and had a similar experience working in a school. The teacher complained the Smartboard touch capability wouldn't work in the morning, but worked in the afternoon. I said nonsense. Went in there and surely it didn't work, but I noticed a bit of a glare from the reflection of the light on the window. I asked her to turn down the shade and the Smartboard instantly started working... felt awesome lol.

20+ years ago, machines with a monochrome and a color monitor. One machine the color monitor would fail every afternoon.

Turns out that for some reason there was a little notch cut in one slat of the blinds. (Presumably to fit around something that was no longer there.) That allowed the sunlight to strike the video card, apparently that was just enough heat to push it over the edge. (This was before PCs were full of cooling fans.)

As support IT in an office, I have a lot of mouse "issues", particularly with the wireless Apple Magic Mouse ... using it turned around 180 deg., making things disappear by not recognizing that the surface can be used to scroll horizontally, battery dying ... to name a few.

We had an xbox 360 that kept ejecting the CD. Later we discovered that it was due to the sunlight coming from the door. After putting it in a dim place the issue never recurred.

> after a few minutes

Savage...