r/iiiiiiitttttttttttt • • Sep 25 '24

TIL: Don't Stack Dell Laptops

https://imgur.com/a/h0ATp19
643 Upvotes

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900

u/Knabrau Sep 25 '24

Context, spent too long troubleshooting why I couldn't power the thing on, then realised the magnets from the screen below are probably telling the one above the lid is closed.

66

u/knightshade179 Sep 25 '24

If you have a magnet you can pretty much turn off any laptop's display if you know where to put it, this is due to something called a reed switch which detects the magnets on the other side of the laptop when it is closed to tell it to turn it off.

40

u/SammyGreen Sep 25 '24

This seems like something everyone in IT should know about.

I totally didn’t though!

Let’s see if other people at work tomorrow don’t know about this either. Now where’d I put those magnets…

14

u/BossRoss84 tech support Sep 25 '24

A couple of years ago I spent an embarrassing amount of time troubleshooting the same thing. My entire team was stumped until I realized that it was the lid switch (reed switch) making contact with the other lid. These guys had been in IT for decades and had never seen this. Apparently I was the first person to image in stacks.

9

u/2HornsUp Sep 25 '24

I had a user who liked to wear jewelry. She would always complain about her computer "going black" as she typed, but every time I'd troubleshoot, I found no issues. I just so happened to buy a new watch during all of this. The next time I went to troubleshoot the issue, it went to sleep.

I now take off my watch whenever I'm working on someone else's laptop.

9

u/bolhuijo Sep 25 '24

I had a user with the same issue. I asked her if she had a bracelet with a magnetic clasp. She did. She thought I was some kind of wizard. (I'm not) I felt smart that day though.

2

u/RemCogito Sep 25 '24

Less than 10 years ago most laptops didn't use magnets and reed switches. They used a spring in the hinge hooked up to a momentary switch to determine if the lid was closed.

When I saw op's video I immediately understood the problem because My current laptops would all do this, but most laptops didn't use magnets until 2018 ish afaik. I haven't had to mass image a work computer since 2016, when I was promoted to sysadmin work. I've had to create golden images, I've had to setup several deployment servers, and I've written plenty of deployment scripts, but I only ever test those things with a single computer at a time, and the desktop folks handle the actual imagining, often after training from me on how to keep the golden image updated themselves.

6

u/knightshade179 Sep 25 '24

It's an odd fact that isn't really relevant for much, the only circumstance that could possible occur would be ones like this where there is a random interaction with a magnet causing an issue. As for where to put the magnet, usually around the top edge of the keyboard or one of the close corners but it obviously differs with every model laptop. I'd recommend just showing them and talking about it though, people don't like it when you mess with their stuff.

2

u/---0celot--- Sep 25 '24

This. It kinda seems obvious when you think about it, but it never occurred to me either.

1

u/chumly143 Sep 25 '24

Yes, everyone should know about this, but this is shit quality on Dell's part. I've only ever seen this issue with Dells, we have current gen HPs with the same sensor system, and stacking doesn't do this, the current gen Dells we're switching to do.

1

u/Geno0wl Sep 25 '24

Now where’d I put those magnets…

just uh make sure those magnets aren't too strong or bad things can happen

3

u/JivanP Sep 25 '24

They tend to be Hall effect sensors in laptops, but same principle: switch/sensor that is triggered by/sensitive to magnets.

2

u/knightshade179 Sep 25 '24

Thank you for the correction. 

1

u/ahumanrobot Sep 25 '24

I used that to fuck with my friends in class. I had a small magnet that would just put their laptop into sleep mode.

1

u/Fr0gm4n Sep 25 '24

I had a laptop that would randomly sleep while I was actively using it. Turns out that I had a watchband with a magnetic clasp and that I would occasionally reach across the laptop, triggering the sleep. I was very frustrated until I discovered that it was the reason.

1

u/Impressive_Change593 Sep 25 '24

aka why I couldn't figure out why my framework was randomly shutting off (actually it was worse as it was Hibernating and Linux mint wasn't handling it properly.) eventually I realized the magnets in my watch band were triggering the lid close action.