Oh wow this is a fantastic write up! I really appreciate the effort you put into this. You’ve certainly given me lots to ponder over. I wonder if there is some credence to the humidity issue. Id have to do some digging on when the issue occured and what the conditions were like but some of the locations do get humid.

Oh that sounds like a nightmare lol how did you even realize it was the office chair?

Ooooo now this is something!! Ive always had a hunch that the way power is being injected into the motor was causing the issue. The serial device is connected by a DB9 port. The RS485 signal A, B and ground then gets accompanied by power to drive the motor. The serial port from the computer goes into this power injecting box and then the box goes to the moto and controllerr.

The grounds should be connected correctly. But now youve got me thinking about these boxes. Modifications have been .are to them overtime, so its totally plausible that something in there is causing a surge to get back into the computer.

Thanks for the response!

Should have been more clear about the remote part. The systems operate remotely from me, I can access them via the internet. The users need to use the screen to operate it. This is just a windows 11 computer after all.

As for the router information, thats part of the reason I know there is power to the entire thing. I can access the router page and see that the link speed was negotiated correctly, at 1gb per second. If they unplug the ethernet, the port reads disconnected.

But 0 packets are getting sent from the computer. I believe those are ARP, but the router page doesnt define it. Just has a table with packets in and packets out. Packets going in will usually have a couple from the router. Always 0 with packets coming out. Theres actually a ping function built into the router, and that doesnt respond at all.

BIOS is not setup during boot to use any sort of networking. No PXE boot or anything like that. On this particular motherboard, you have to enable the network stack, so I dont think its that. System is setup to always turn on when power is applied to bring all the other components online together.

Anyway, thanks for taking time out of your day to respond!

Okay?

sit there with a black screen after turning on and not reaching the windows bootloader

Were you able to access the BIOS? We’re unable to access the bios when the computer stops working.

Also, even more frustering, we have a dedicated power supply to run the whole operation. If the system was able to turn on, I could read the voltages and amps going into the system. Weve swapped out the power supplies as well but that doesnt seem to resolve the issue.

Now that is an interesting idea. I cant go into to much detail about the exact components but this particular port drives a DC motor. Power is injected to drive the motor.

Tbh, im not very familiar with ground loops. Have you had experiences with ground loops before?

I appreciate the quick response as well!

I dont mean to be rude but I dont think thats relevant without doxxing myself. You can look at my post history to know that I’m in the US and my computers are as well. They are far enough that I cannot travel to them.

Bless your heart

I appreciate the sentiment, people being nice to eachother should always be encouraged. But thanking people always seemed odd to me. I drank a lot. :(

But Granny Smith Apple.

Thankfully, I’m doing better now :)

Theres a couple of mistakes there. For example, a Bronze star would be above the Navy Marine Corps Achivement ribbon since its a much more prestigious medal. I cant tell what the devices are but this is the stack.

Row 1

1. Navy Marine Corps Achievement Ribbon

Row 2

1. Navy Marine Corps Combat Action Ribbon
2. Navy Marine Corps Presidential Unit Citation Ribbon
3. Marine Corps Good Conduct Ribbon

Row 3

1. National Defense Service Ribbon
2. Iraq Campaign Ribbon
3. Global War on Terrorism Expeditionary Ribbon

Row 4

1. Global War on Terrorism Service Ribbon
2. Humanitarian Service Ribbon
3. Navy Sea Service Deployment Ribbon

Source: Eaten a couple crayons.

Windows Hello ties the PIN to the TPM of the computer. It’s not just you having a pin, its the pin + the crypto secret loaded on the device. Thats why its more secure then just a complex password.