15pin vga, hot swappable or not ?

[fenix]

Hi,

I was always told (maybe in error) to never disconnect
a vga monitor plug from the motherboard onboard video or from a graphic card unless the power was off.

A few days ago I was shocked to see a computer tech with
his own business (alot of it), unplug a monitor while the computer was on. I inquired about it and he said that it was a common practice and that he had been doing it for years.

what say you all ?

Power off necessary or not ?

Thank you for clearing this up for me.

 

[vacunita]

I've never had any issues with it. I'm mean its not like pulling out the video card with the computer running mind you.

I see no real hazard. Maybe turn off the monitor before you unplug the vga cable, just to be safe.

**In any case, i be willing to bet that everybody here does it at some point or another. Its nothing to be ashamed of, its perfectly normal. **





----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[gbaughma]

Yeah... i've never had an issue with it... I mean, look at what a KVM switch does....



Just my 2¢

"When I die, I want people to say 'There was a wise man' instead of 'Finally, his mouth is shut!'" --Me
--Greg

http://parallel.tzo.com

 

[fenix]

Hi vacunita,

Thx for the reply. I don't remember if the monitor was on or off.

I bought this computer from a shop for a friend of mine. A Via chipset, Pentium D, 2.66ghz, store built (PM8PM). To get the price in our range, I had the store guy remove the somewhat cutting edge graphic card and just went with onboard graphics. It was at this time that he unplugged the monitor cable with power on, but don't exactly remember why he did this, I didn't observe everything he was doing and it was 3 months ago.

Last night the computer owner said (from what I can gather) that there were "blue shaded little boxes floating around inside of windows". (??) When I went over today and turned it on to check it out, I noticed a visible cycling in the display. (CRT) Checked the refresh rate and it was at 60hz. Reset it to 75 and the display became solid with no flickering.

Then, as I was trying to duplicate the floating boxes, my client unplugged the computer by accident and it seemed to blow the onboard video output.

Monitor flickers once when powered on, but no display. And also we get one real long continuous beep that repeats continuously immediately on power up. On one of the attempts/reboots/hard power downs we got a one long and two shorts beep code.

The reason for the original question was to see if the onboard graphics could have became damaged when he unplugged the vga cable.

So to expond upon your "pulling out a video card sentence", if he unplugged the agp card with power on, would that be a 100 % failure rate, or could doing that set up a soft failure for a later time, like after about 40 hours of usage ?

If you or someone can help out with the beep codes, and answer any questions I'd appreciate it. If all else fails,
and trying to avoid a mobo replacement, may trying a graphics card be a work around ? Or does a blown onboard video output affect all graphic systems ?

Thanks for any more info before I present this scenario
to the computer store.

 

[vacunita]

Pulling out a video card with machine on, is not only devastating to the card, but can also cause damage to the mobo. Usually the damage is immediate.

However pulling out the VGA cable has never caused any problems that i'm aware of.

You'll need to find the meaning of those beeps, for that we'll need the Mobo Manufacturer and model. as each motherboard has its own beep codes.

Adding a separate video card is a good workaround. onboard video should not affect addon cards in any way, unless the motherboard is the one that actually suffered the damage. in any case trying an addon video card can rule out problems with the motherboard.

It could also be that the moniotor is the one thats gone, have you tried it in another machine, see if it will work there?

----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[ASG0856]

2 pennies worth.
Unlike USB which is designed to be removed with power on, removing the vga plug is a very bad idea. Remember this is live. Static or a spark could be generated which could cause all sorts of problems. If a pin is bent in the process, this could cause a short which, in all likelyhood, would blow the mainboard.
Just because someone has always done it with no problem does not make it right!

 

[cdogg]

...removing the vga plug is a very bad idea

fenix,
Just like the quote here from ASG0856, the advice you've been given is a bit exaggerated.

A PC monitor only "receives" an output signal from the video port. As long as you turn the monitor off prior to unplugging it from the back of the PC, the cable connection becomes as dead as a door nail. There's no risk of shock or "magical" damage as a result of disconnecting it while the computer is on.

Now if you leave the monitor on while you unplug it, there is a slight risk that part of your body is making contact with the screen. This can transfer a lot of static from the screen (through you) to the metal surface of the video port as you're disconnecting the cord. Turning the monitor off first reduces this risk as well.

About the only thing I can think of that could happen is to make the mistake of not unscrewing the monitor cable well before pulling it out of the port. This can possibly bend the video card enough to affect its pin contact in the slot on the motherboard while the PC is running, which could have devastating consequences. But as long as you're not pulling too hard and your video card is screwed into place, that shouldn't be a real concern.


At the very least, I classify the phrase "very bad idea" to mean that there's a good chance something is going to happen so don't do it. That is not the case here. Every tech I've ever known does it. To my knowledge, no one has ever witnessed an explosion, fire, or hair-raising static (let alone a damaged video port) from doing a "hot swap". It's commonplace where I work, where we typically replace or move 20-30 monitors each week.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[paparazi]

I guess all I can say is DITO to cdogg's comments.
I work in a PC custom build shop where we repair/build hundreds of PC's each year. We have NEVER had an issue with hotswapping monitors with what has to be several thousands of PC's.
Your beep code could be VGA but also try removing and refitting the ram (plus reseat the power connectors to the motherboard)
Martin


We like members to GIVE and not just TAKE.
Participate and help others.

 

[LWComputingMVP]

The only problem I've ever seen with unplugging live cables from the exterior of a computer are with SCSI and PS/2. Unplugging a VGA cable is about as safe as can be and I don't give it a second thought. And even PS/2 nowadays is much better at handling that then it was back in the days of the 486. Note: some USB storage devices have issues, but nothing a reboot can't usually fix.

 

[fenix]

Thank you all ! As always this is THE place to go
for good information. I'll post any results as I get them.

fenix