Are monitors hot swappable?

[warbean]

Anyone know if the latest LCD monitors using DVI technology are hot swappable? I have 2 DVI outputs on my 7900 GT and was testing my LCD monitor on both (Syncmaster 204B). When I unplugged from one and plugged into the other, it played the typical "USB" unplug/ plug in noises, which made me think it might work. Unfortunately, it did not and I had to turn off / back on to get it to work.

I was wondering if the trend in hot swappability of computer input devices have extended to monitors, and if not, whether or not someone risks ahrdware damage by "hot" plugging in a monitor into a computer.

Any thoughts?

 

[ProfJohn]

You had to turn the monitor off and on or the computer off and on?
With the old RBG I am pretty sure you could hot swap, but DVI may be a different ball game.

 

[warbean]

Had to turn off computer.

SOmeone convince my paranoid self that my precious 7900gt is safe!

 

[ProfJohn]

I am guessing that the computer cannot deal with a swap like that. It is putting the output to the one DVI so trying to change DVI ports and the computer might not even notice. When I pluged in a second monitor to my cheapo card nothing happened until I changed the setting on the monitor control panel.

Maybe you could have done the same, to bad you couldn't see the mouse to make the change.

 

[JimPhelpsMI]

Hi, Yes, but might probably need a reboot.

Luck, Jim

 

[Lord Evermore]

From an older post where somebody was having the same issue with a DVI monitor, it seems like Windows (and perhaps the hardware itself) does not like losing the monitor signal to the DVI port, and shuts the port down. Just plugging it back in doesn't reset the connection. If you had another monitor plugged in at the same time, you could probably do something like "Scan for hardware changes" in Device Manager, or even just disable and then enable the second port in the display properties, in order to make Windows check the port again, if it's not a hardware-based thing. If you set it up before you actually unplugged, so that all you had to do was hit the Enter button, it'd probably work.

VGA ports are probably sort of "dumb", by comparison, so it doesn't care if there's nothing receiving the data signal. Technically VGA connectors weren't designed to be hot-pluggable, just like parallel and serial ports weren't technically supposed to be plugged while the computer is on.

DVI does have a "hot plug detect" pin, but I dunno if that guarantees that a video card or monitor is designed to handle it. This could be the pin that's causing the video card to shut down the port in order to prevent the other signal pins from frying.

Found Microsoft's hot plug detect information. So it seems like the idea of forcing the port to disable/enable in the driver would most likely do exactly what you need. Depending on the exact hardware involved and its drivers, some devices would actually automatically detect the new device and enable it.

 

[warbean]

great; so at the very least, there's no hardware danger to the video card or monitor for doing this infrequently, even if the swap doesn't 'work'?

THanks all for the info

 

[imported_Imp]

Originally posted by: Lord Evermore
VGA ports are probably sort of "dumb", by comparison, so it doesn't care if there's nothing receiving the data signal. Technically VGA connectors weren't designed to be hot-pluggable, just like parallel and serial ports weren't technically supposed to be plugged while the computer is on.
DVI does have a "hot plug detect" pin, but I dunno if that guarantees that a video card or monitor is designed to handle it. This could be the pin that's causing the video card to shut down the port in order to prevent the other signal pins from frying.

That's a bit disconcerting. I've been hotplugging a serial port for my PDA into a lot of computers at various offices. Hope I didn't fry anything, but the again, my "home" office one is hit the most and it hasn't died......yet.

 

[Lord Evermore]

Originally posted by: Imp
That's a bit disconcerting. I've been hotplugging a serial port for my PDA into a lot of computers at various offices. Hope I didn't fry anything, but the again, my "home" office one is hit the most and it hasn't died......yet.

It's one of those things where people do it millions of times, and everything is overengineered so that it's usually safe, yet it's not designed for it, so when it does rarely cause a problem, there's nobody to blame but yourself.

 

[bruceb]

You won't kill a serial port by hot plugging .... especially if the device connected
to the serial port is turned OFF

Now as to hot swapping the Monitor .... unless the user manual explicity states
that you can DO it, then I would not swap monitors while either the PC or the
Monitor is Turned ON .... better Safe than have to replace a video card or monitor

 

[networkman]

I've been hot-swapping monitors at will for many YEARS and never encountered a problem, aside from the next monitor not being able to support the higher resolution that the previous one did.

Seriously, even LCDs with DVI plugs - I have yet to encounter any problems and I've been hot-swapping to do Ghost sessions and other configurations on literally hundreds of machines with zero problems.

 

[WarCon]

If you think about KVM switchs, there isn't any real difference between hot swapping and switching monitors and keyboards/mice with the KVM switch.

I personally don't hot swap because I am never in that big of a hurry that I can't shut something down to (un)plug anything in.

Don't know about DVI though........

 

[lazy0ne]

I personally have hot swapped a monitor and fried a video card. This was about 7 years ago, but it did happen. Take it for what it is worth. I still hot swap when I need to.

 

[Rage187]

Originally posted by: Lord Evermore

Originally posted by: Imp
That's a bit disconcerting. I've been hotplugging a serial port for my PDA into a lot of computers at various offices. Hope I didn't fry anything, but the again, my "home" office one is hit the most and it hasn't died......yet.

It's one of those things where people do it millions of times, and everything is overengineered so that it's usually safe, yet it's not designed for it, so when it does rarely cause a problem, there's nobody to blame but yourself.

correct, you can blow a serial port on a mobo by hot swapping serial devices, but usually consumer level serial devices are tolerable.

 

[gtjr]

if it aint usb dont hot swap

 

[Lord Evermore]

Originally posted by: gtjr
if it aint usb dont hot swap

What if it's FireWire? Or a proper SATA setup?

 

[JimPhelpsMI]

Hi, There is no danger to "Hot Swapping" serial ports or monitors. Jim

 

[mwmorph]

Originally posted by: JimPhelpsMI
Hi, There is no danger to "Hot Swapping" serial ports or monitors. Jim

Monitors arent designed to be hot swapped and if done wrong, you can fry the monitor, possibly the pc and the surge connector its connected to. A coworked did it once. The sure destroyed the monitor, the video card, power supply and turned all other pcs connected to the surge protector off since the surge protector strip went off. Also the monitor had a nice burning smell and sparks came out. The coworker didnt last long in the job either.

We were using D-Sub and older monitors and pcs though(233mhz to 466mhz pcs, 15" monitors from 1996-1998.)

 

[warbean]

well it's been a few days now and everything seems fine. if something was fried, i'd hope it would have been apparent by now.

 

[JimPhelpsMI]

Hi Again, There are no high power or high voltage in the Monitor cable. Should not be able to damage anything. Jim