Explain this weird computer behaviour (screen goes blank when user stands up)

Weirdest thing today - the developer in my team finally lost patience over a niggling little problem that has apparently been going on for quite a while.

His desk is equipped with a pair of flat monitors plugged into a Startech docking station, powered by an I7 laptop.

When he stands up from his chair, both monitors go blank for about a second simultaneously.

Here’s the weird thing: It happens every time for him, but it doesn’t happen if anyone else sits in his chair and stands up. Not once. We tried three different people in the chair - one guy who is bigger/heavier, a girl who is smaller/lighter and me (about the same size and build as the dev. Nobody else can make it happen, even if we carefully mimic all of his actions.

There are no power cables anywhere near his chair or feet. The thing happens even if he isn’t touching the desk before, during and after standing up.

We considered some sort of static electricity thing, but it’s been happening for days/weeks, regardless of his clothing. We considered some motion-related effect from a bluetooth device such as his phone, but it’s just lying there on the desk, and he diesn’t have anything else.

I guess the simplest explanation is that he has somehow engineered it, and he’s playing a prank on us, but I don’t think it’s this.
So what should we do next to determine the cause of this odd phenomenon.

Maybe someone else is having a prank with him?

Seriously, have you tried switching out either monitor?

Does this behavior happen if your co-worker sits at anyone else’s desk?

There are only three of us, and him in the office - I don’t think any of us are pranking him.

I don’t think it’s the monitors, as they both blank out and come back exactly simultaneously - so if it’s a piece of kit at fault, I think it has to be the docking station, the computer or mains power.

The problem only occurs for this user at his own desk. We swapped out the chair and the problem stayed with the user/computer.

Does he have a pacemaker or other electronic device on him that nobody else has?

Does he have a magnetic personality?

Have you completely ruled out anything that may be in his pockets or attached to his body? A belt buckle, maybe?

The fastest way to do this would be to have him strip completely naked and remove the clothes from the room. If that clears the problem, have him replace one item of clothing at a time until the problem reappears. Of course, you could do the reverse and have him take off one item at a time, but starting with everything would quickly rule his clothes in or out.

Are you pranking us?

Try swapping out a monitor, the docking station, or the cabling.

Make sure the cable connections are tight and the cases are all securely closed. If you can’t swap out the CPU box, try moving it to a different location. We had a weird problem with a PC only booting on the floor, not on the desktop next to the monitor. We called it bad feng shui. Turned out to be poorly shielded case for the CPU tower and the monitor. We replaced the monitor and all was well, even with the same CPU case. RF problems can be a bear to debug.
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Sounds like the screen is fond of him and suffers separation anxiety when he gets up to leave.

The problem is that he does the actual thinking for the computer, but can’t do it sitting down. So he stands to reason.

When he stands in front of a mirror, is there any reflection?

Does it happen when he stands up from someone else’s computer?

It’s the pixies.

The way the problem is described, it’s got to be the docking station. It seems like something is causing the docking station to momentarily lose contact with the laptop, or lose power.

I’d try plugging one monitor directly into the laptop’s aux video port, then the other, bypassing the docking station. Chances are they’ll both stay on. After that, I’d try a different power cable to the docking station.

Does the guy’s chair rest on one of those plastic deals that’s supposed to protect the carpet? Is there any chance that the change in pressure as he gets up is shifting the carpet protector enough to jiggle the desk? Just a thought.

If none of the above fixes it, blame North Korean hackers.

Nope. He’s got a waveceptor watch, but this is not a transmitter (and I have a similar watch, and the screens don’t go blank for me)

That is my go-to response when someone complains of vague malfunctions in their computer.

It’s been happening for weeks with no common factor in his clothing.

I’ll suggest that tomorrow.

Well, that is the simplest explanation, but no. I have video evidence (will post later if required)

We haven’t tried that, but there aren’t any other setups that are very similar to his.

I think so - and I think it’s got to be some magnetic field thing, because it happens without him making any contact with the desk or its contents.

Update: we think it’s his shoes and the carpet - generating a static charge.

It probably means the docking station (or something plugged into it such as the mouse or keyboard) is especially sensitive to changes in the field (although he’s not touching anything on the desk when he stands up, if he’s charged and moving, then there is a field changing).

Probably indicates near future failure or this piece of kit…

Don’t let him stand up. Tell him when he can stand up. Then if there is some sort of timer, he would not know when exactly you were going to tell him to stand up.

Place aluminum foil around him. If he has some sort of wireless device, that would block the signal.

We already did that. If he’s driving it to prank us, it would have to be motion activated somehow, but I don’t think he is.

Here’s a couple of things to try:

  1. Does it matter how long he sits before he stands up? If he is sitting for an hour and it happens, but the other people are only sitting for a few seconds, then you haven’t performed an “apples to apples” comparison. Try having him sit for the same amount of time that the other people do and see if it happens.

  2. Do the other people simulate the same movements as he does? That is, if he is using his computer keyboard and mouse, but the other people are just sitting at the desk, then, again, you haven’t performed an “apples to apples” comparison. All three people need to do the same thing. (I suggest sitting down, typing the exact email, and sending it.)

Bad feng shui?

OK, I’m mostly joking, though some years back we suspected that was the issue with a secondhand computer we’d purchased. Worked fine at the co-worker’s house; crashed on or shortly after startup at ours. He took it back, it worked fine. A couple rounds of this, a new hard drive - and we ultimately figured out it was interference from the monitor. The case on the computer was less-shielded and it was RF interference.

So I’m wondering if somehow, the co-worker is acting as an antenna and this setup is particularly sensitive. Jewelry, implants or whatever sort (steel plate in skull, surgical pins in bones, etc.).

Check his feet. Are they flat on the floor while he’s sitting, or only when he stands?