In meetings, I often see people detaching the VGA connector from one running laptop and connecting it to another, while the projector is still on.
Is this 100% risk free, and OK by design of the VGA standard? If there's a risk involved in hot-plugging VGA, can it be removed by turning off or suspending either laptop, display, or both?
I see this being done all the time without causing disaster, so clearly I'm not interested in answers stating "we do it all the time, so it should be OK!".
I want to know if there's a risk - real or in theory - that something breaks when doing this.
EDIT: I did an internet search on the topic, and I never found a clear statement as to why it is safe or unsafe to hot swap VGA devices. The typical form is a forum question asking basically the same question as I did, and the following types of statements
- Yes it's hot swappable! I do it all the time!
- It involves some kind of risk, so don't do it!
- You're some kind of moron if you think there's a risk, so just do it!
But no explanation as to why it safe or not...
Joe Taylors answer below contains a link to a forum post and answers that basically give me the same statements as mentioned above. But again, no good explanation why.
So I looked for an actual manual for a projector, and found "Lenovo C500 Projector User’s Guide". It states on page 3-1:
Computers and video devices can be connected to the projector at the same time. Check the user’s manual of the connecting device to confirm that it has the appropriate output connector.
Attention: As a safety precaution, disconnect all power to the projector and devices before making connections.
But again, no good explanation.