Electrostatic discharges from chairs can interfere with USB and display signals:
"Surprisingly, we have also seen this issue connected to gas lift office chairs. When people stand or sit on gas lift chairs, they can generate an EMI spike which is picked up on the video cables, causing a loss of sync. If you have users complaining about displays randomly flickering it could actually be connected to people sitting on gas lift chairs. Again swapping video cables, especially for ones with magnetic ferrite ring on the cable, can eliminate this problem."
"This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation."
That seems to be the general bend of the diagnostic help over reddit, though it seems we may never know for sure. Its been 30 days since Mr. Kanasta's last post.
KaptainKanasta, if you're out there, I know I speak for others who would love to hear if the chair was indeed the culprit. Though if it wasnt the chair and was indeed a malevolent spirit, I fear the worst.
The top comment says it's the system sound for inserting/removing a USB storage device. I'm guessing it's a loose connector or shorted wire and the vibration from standing up and moving the chair is causing it to briefly disconnect.
In such cases I suggest to install some sort of accelerometer near computer, best something like arduino with sensor, may be possible to use smartphone with app, and monitor accelerations and try to make correlation of acceleration, sound and computer logs (sure better if switch to debug level).
I have lot times seen issues, when in concrete building, sit/stand causes vibration, which temporary turned off ground contact of some device and some strange unwanted things happens.
The most annoying in my life, where restarting of hdd drive. At beginning I thought, it caused because drive is broken.
But than I checked connections and found just weak molex ata power connector - than i just use pliers to slightly bend contacts and those effects disappear forever.
andreasley|3 years ago
"Surprisingly, we have also seen this issue connected to gas lift office chairs. When people stand or sit on gas lift chairs, they can generate an EMI spike which is picked up on the video cables, causing a loss of sync. If you have users complaining about displays randomly flickering it could actually be connected to people sitting on gas lift chairs. Again swapping video cables, especially for ones with magnetic ferrite ring on the cable, can eliminate this problem."
https://support.displaylink.com/knowledgebase/articles/73861...
Demonstration:
https://www.youtube.com/watch?v=voW5kEI7JKE
A paper about this phenomenon, titled "A New Type of Furniture ESD and Its Implications":
https://emcesd.com/pdf/eos93.pdf
hulitu|3 years ago
Design and test is hard /s
IntrepidWorm|3 years ago
KaptainKanasta, if you're out there, I know I speak for others who would love to hear if the chair was indeed the culprit. Though if it wasnt the chair and was indeed a malevolent spirit, I fear the worst.
madengr|3 years ago
[deleted]
weare138|3 years ago
simne|3 years ago
I have lot times seen issues, when in concrete building, sit/stand causes vibration, which temporary turned off ground contact of some device and some strange unwanted things happens.
The most annoying in my life, where restarting of hdd drive. At beginning I thought, it caused because drive is broken. But than I checked connections and found just weak molex ata power connector - than i just use pliers to slightly bend contacts and those effects disappear forever.