Check if your IKEA chair is compatible with your screen • Hacker News Board

Re: Check if your IKEA chair is compatible with your screen

#61

Post by lucb1e » Fri, Apr 28, 2023, 5:36 PM UTC

tambourine_man wrote: post #58

lucb1e wrote: post #47

An electric lighter does this to my mouse when I zap specific objects with it, such as a screwdriver. I tried distances up to about 1.5 meters away from the mouse. The only reason I initially noticed is because I saw the red light turn off that was coming faintly through the holes I drilled in the top to let a heating element that I had built in heat my hand better. (Spoiler: the holes didn't do anything, but I did n…

You have to scream back at them: https://m.youtube.com/watch?v=tDacjrSCeq4

mentally calls hard drive in datacenter video - clicks - did not disappoint :)

I tried this but could not reproduce it by the way.

Re: Check if your IKEA chair is compatible with your screen

#62

Post by sophacles » Fri, Apr 28, 2023, 5:36 PM UTC

kstrauser wrote: post #33

blueflow wrote: post #14

I once had the problem that running make with too many parallel jobs (-j) would change my keyboard layout. The machine was some laptop mainboard glued to the backside of my monitor, and the USB socket came out at the top of the mainboard. On its way down, the USB cable for the keyboard passed across the whole mainboard. On high load, the mainboard created enough interference to cause the connection to reset, re-hotpl…

This is the greatest thing I've read today. I love when software and the real world have entirely unexpected interactions. And by love, I usually mean hate, especially when I'm the one that has to debug them.

These sorts of things make for good war stories. I find a trick to improve my attitude while dealing with them is to remind myself "this will be a good story at least, and I'll be glad it happened once I'm regaling others with it".

Re: Check if your IKEA chair is compatible with your screen

#63

Post by sudobash1 » Fri, Apr 28, 2023, 5:37 PM UTC

I have a nice little window fan that I've had for years, but last time I pulled it out it started blanking my monitor when I flip it on. I've assumed that this is some sort of ESD issue, but I don't have any great ideas on how to troubleshoot or resolve it.

Re: Check if your IKEA chair is compatible with your screen

#64

Post by mat_epice » Fri, Apr 28, 2023, 5:37 PM UTC

tambourine_man wrote: post #50

blueflow wrote: post #14

I once had the problem that running make with too many parallel jobs (-j) would change my keyboard layout. The machine was some laptop mainboard glued to the backside of my monitor, and the USB socket came out at the top of the mainboard. On its way down, the USB cable for the keyboard passed across the whole mainboard. On high load, the mainboard created enough interference to cause the connection to reset, re-hotpl…

https://xkcd.com/1172/

I was about to dig this one out myself!

Re: Check if your IKEA chair is compatible with your screen

#65

Post by tzs » Fri, Apr 28, 2023, 5:37 PM UTC

I thought that the use of differential pairs in these various systems was supposed to protect against outside interference?

Looking at the pinouts for HDMI and DisplayPort I see that they both use differential pairs for all the high speed lanes that carry audio and video.

For the lower speed channel for other things such as control functions DisplayPort uses a differential pair. HDMI does not. Does that make HDMI more sensitive to interference?

Re: Check if your IKEA chair is compatible with your screen

#66

Post by lucb1e » Fri, Apr 28, 2023, 5:39 PM UTC

etiam wrote: post #3

Remotely related, my screen makes a noise, somewhere between static and a whine, while displaying certain text files. Minimizing or closing the editor stops the noise, getting the text back on display restores the noise. I suppose it's some sort of resonance phenomenon.

Spreadsheets are what do it for me. Haven't noticed it on anything else. Only whole-screen spreadsheets. Opening the start menu (covers maybe 1/5th of the screen width and half the height, so 10% overall I'd guess) is already enough to break the pattern. At 110% or 90% zoom it does not happen at all, it needs to be the default zoom level. It's also noticeably less if there are colored cells.

You can dial the screen's volume by making the libreoffice window partially transparent (I have that bound to scrolling on the title bar). This is on an Acer 1920x1080 (~23"?) screen from around 2009.

Re: Check if your IKEA chair is compatible with your screen

#67

Post by kstrauser » Fri, Apr 28, 2023, 5:39 PM UTC

sophacles wrote: post #62

kstrauser wrote: post #33

Earlier quoted context omitted.

This is the greatest thing I've read today. I love when software and the real world have entirely unexpected interactions. And by love, I usually mean hate, especially when I'm the one that has to debug them.

These sorts of things make for good war stories. I find a trick to improve my attitude while dealing with them is to remind myself "this will be a good story at least, and I'll be glad it happened once I'm regaling others with it".

Oh, you know it! That's going to be a great tale to bust out for years to come.

Re: Check if your IKEA chair is compatible with your screen

#68

Post by l72 » Fri, Apr 28, 2023, 5:41 PM UTC

tetris11 wrote: post #44

blueflow wrote: post #14

I once had the problem that running make with too many parallel jobs (-j) would change my keyboard layout. The machine was some laptop mainboard glued to the backside of my monitor, and the USB socket came out at the top of the mainboard. On its way down, the USB cable for the keyboard passed across the whole mainboard. On high load, the mainboard created enough interference to cause the connection to reset, re-hotpl…

I currently have an RPi4 mounted to the back of my TV for easy Kodi streaming, but I never considered using the business end of a laptop. I'm sure I have a decade old laptop with a broken screen sitting at the bottom of a shelf somewhere...

I invested in a frame.work laptop. If I ever purchase a new mainboard, I'll get this cooler for my old mainboard and use it as a server or mount it to a TV:

https://www.coolermaster.com/catalog/cases/mainboard-case/fr...

Re: Check if your IKEA chair is compatible with your screen

#69

Post by MikeBVaughn » Fri, Apr 28, 2023, 5:41 PM UTC

I have this exact chair and I've spent the past three months thinking the cheapo wired mouse I bought I was leaking voltage, or that I had a FUBAR HDMI cable.

I cannot tell you how much of a balm this is for my sanity.

Re: Check if your IKEA chair is compatible with your screen

#70

Post by sgtnoodle » Fri, Apr 28, 2023, 5:41 PM UTC

etiam wrote: post #3

Remotely related, my screen makes a noise, somewhere between static and a whine, while displaying certain text files. Minimizing or closing the editor stops the noise, getting the text back on display restores the noise. I suppose it's some sort of resonance phenomenon.

Indeed. It's the frequency of pixel changes causing ripples in voltage rails, subsequently causing inductors in switching voltage regulators to physically resonate at audible frequencies.

There's specific test images you can find online, designed to maximally stress voltage rails in LCDs. Lower end monitors can actually get enough voltage ripple that the image quality visibly degrades.