# Can a video card damage a monitor?



## ikarihiokami (Feb 8, 2011)

I posted this in another forum and no one replied.

Let me give you the scenario. I have a SAPPHIRE 100260SR Radeon HD 4850 X2 1GB 512-bit (2 x 256-bit) GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card. The card has 4 dvi ports so I can have 4 monitors attached to it. 2 of my monitors are digital with dvi cables, one is a wacom tablet that uses a dvi cable, but one was an only flat panel analog monitor that used a vga cable with a dvi adapter. 

Just recently the display started to go out on my old analog monitor. I thought to myself "well it's old so I'm not surprised". THe computer still saw it and if I turned it off and turned it back on the display would show for a few seconds. Well I wanted to be sure it was just the monitor and not the video card port, so I hooked up the monitor over on another computer and sure enough it wasn't working. Then hooked up the other computers monitor (another analog monitor with a vga cable BTW) and the port still worked. 

Well the next day the other monitor started to flicker to the point where you couldn't see what you were doing. It has since stopped, but what I'm wanting to know is is it possible that my video card killed my old monitor and damaged the other one I hooked up to it? Or is it a coincidence that the other monitor started to act funny? I don't want to hook another monitor up to it if it's just going to kill another monitor.

On a side note I did switch around my monitors to that port to see if it would work and none of my other monitors have shown signs of having problems. I switched them around several times and only once did a display not show, but I think it was because I was screwing around too much and my computer's display setting were getting ticked at my (so to speak). By the time I was done screwing around I had to re do how I wanted my monitors laid out. Now that I have my setting back to normal and I hook another monitor up, the monitor works fine. I just don't want to hook another monitor up to it only for it to die.

Since then the another monitor that started messing up is working fine for a while now and my new monitor hasn't shown signs of problems while hooked up to my video hard.


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## Wrench97 (May 10, 2008)

Never say never, but it's not something I've seen nor heard of before.
If I had to guess I would say moving the 2nd monitor caused the flickering screen more so then the video card port.


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## r00x (Feb 13, 2011)

The reverse is possible (as in the monitor could damage the VGA port) if one is using a laptop on mains and hot-plugs the VGA connector of just the right type of monitor. Rare, though.

The other way round? Even more unlikely, I'd say. I've only ever heard this question asked, never answered.


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## ikarihiokami (Feb 8, 2011)

I appreciate you guys replying. At least someone replied as opposed to the other place.  I just wanted to see if anyone has heard of a problem like this. My new monitor has been working fine for a while and I'm just guessing that my old monitor was just old. It was probably a fluke that the monitor I used to test what was going on started acting up. It is probably just old too and moving it messed with it.


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## dai (Jul 2, 2004)

there used to be a warning if a unsupported refresh rate was set that it could damage the monitor

i never ran into one


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## kbright (Jul 1, 2011)

I believe that it can. I had two identical Hyundai monitors running on my Mac Pro. Both connected to the dual DVI ports on the factory ATI Radeon HD 2600. One day I noticed the second monitor was blank yet the power light was solid blue as it normally is when not sleeping. Yet the screen was black. I could not even get the monitor setting menu to come up on the monitor itself. How ever if a unplugged the signal cable and replugged it I could see a perfect screen for about one second. Or if I changed the resolution on that screen in the OS it would flash a perfect screen for about one second. Remote desktop into the machine shows two fully functional screens at least in software.

I moved the failing monitor to another computer and it behaved the same, perfect screen or desktop for about one second.

So I figured the screen backlighting circuit that turns on the backlighting is messed up.
I put a different monitor on that same second DVi port back on the original Mac Pro and it worked for a about 2 weeks and now it acts the exact same way. I cannot get to local built in monitor menus, yet it will show a perfect screen for about one second then go blank. The first failing monitor was a Hyundai and the second one was a Samsung.

I am beginning to believe that the display adaptor messed with the both monitors backlight activation circuit. Neither monitor will work for more than 1 second on any computer now.

I am now afraid to plug another good monitor into the #2 DVI port on that adapter.


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