Can one damage a PC video card by unplugging the monitor cable?

Question

I have had an argument with a friend of mine, he was trying to prove that unplugging a DVI or VGA monitor cable can cause damage to the video card. I have never heard this before and decided to pull out the lead to demonstrate that it's not true and in fact after plugging it back in the machine has crashed and show on color on the screen.

So, I have reset it and done it again - same thing. After another reset it started showing that same color or just going blank randomly. I am currently using a regular DVI-to-VGA converter, which I though may be the cause of the problem appearing in the first place. So my idea is that probably with a converter you can damage the hardware, but if used a DVI monitor it would work just fine unplugging and plugging back in.

I have always done it before with VGA and can also remember doing it with a DVI cable on another machine.

Solution 1

VGA is hot-pluggable by experience. It works almost all of the time. It is not hot-pluggable by design. The DDC2 pins (I2C device identification serial bus) and the lack of special ground break hardware are the problem.

Solution 2

Your friend is right, plugging and unplugging a live cable can cause damage. It wouldn't always cause damage, but sometimes.

Causing damage may be rare, but unfortunately it looks like you just proved your friend right.

Comments

[errordeveloper]

In fact I have asked this on electronics.SX because I wanted a technical answer with some details of how DVI works, hoping to catch someone who actually read the DVI spec and had experience with it on the low level, but nevermind ...

[Kortuk]

consumer electronics support does not fit on electronics.SE, but if you have a specific question about a spec or line drivers or such please ask. This is a case of having to know how they built their circuit to know if it is a danger and there are many superusers out there that know if this kind of process.

[sawdust]

I tend to agree with your friend, but most people seem to agree with you. Review this similar question: superuser.com/questions/333874/…

[Sirex]

interesting. I've always hotplugged vga, hdmi, dvi, in fact every video connector for many years and have never had 1 single issue.

[errordeveloper]

That's what I had been thinking. So in the case of a DVI (or VGA) what should I do if I need to unplug it? Put a card into some mode or just turn of the monitor first? Or you will say that I need to shut down the computer?!?

[blakey87]

It kind of depends on how safe you want to be, the best would be to shutdown the monitor and PC first.