Troubleshooting video flicker

[CatMoon]

I got a new computer a few weeks ago and I've been having a problem with it, maybe someone has some ideas.

I have two monitors hooked up, a Benq 24” running at native 1920x1200 and a Dell2007FWP 20” running at native 1680x1050. Intermittently one of the two monitors will flash off for just a brief moment, just a quick flicker. It doesn’t happen to both monitors at the same time, and it doesn’t seem to happen in connection to what’s running on the computer at the time. I'd say it happens a few times per hour. Both are connected via DVI.

I was running the same monitors on the same settings on my old Dell without the problem, so I don’ t think it’s monitor related.

I noticed the problem from the beginning with the new computer running under XP, but waited for the Vista release thinking maybe it was driver related. The problem still exists running Vista (32 bit Business) so I don’t think it’s OS related.

I’ve upgraded the BIOS to the latest version. I’ve tried both PCI-E x16 slots for the video card, and tried a different PCIE power cable.

I RMA’d the original Sapphire x1950 Pro card that was sent with the system and tried the Connect3D x1950 Pro I was sent as a replacement. The flash still happened, and in addition the Connect3D card was failing with a “Display driver R300 stopped responding and has successfully recovered.” error every 30 seconds or so when the card was under load (looks like a bad card).

Today I bought a nVidia 7950GT thinking that the problem might be related to the Catalyst drivers or ATI in general. I still have the problem with the nVidia card, so I don’t think it’s related to the video card or video drivers.

Nothing is overclocked and I think I've got most everything running default settings.

I don’t know what’s causing the flicker and can only guess that maybe it’s power supply related or motherboard related. Any thoughts?

My system specs:
Asus P5W DH mobo
4 GB PC6400 DDR2/800 ram
Core 2 Duo E6700 @ 2.66Ghz
various gfx cards
Ultra ATX Modular 700W power supply

 

[leSLIe]

in multi-monitors setups with different brand models you have to be careful regarding the limitations in resolution and REFRESH RATE, you can set different refresh rates for the different monitors and in different resolutions. u can try to play with the refresh rate raise it or lower it.

 

[CatMoon]

Thanks, I think that is the problem. I had the two monitors working before on my old system, but it was with one VGA and one DVI port.

So I think the issue is that if you're running two monitors off one card, both using DVI but at different resolutions/refresh rates then you get the flickers.

To try solving this I'm going to add a cheap second card for the second monitor.

 

[Un4given]

Thanks, I think that is the problem. I had the two monitors working before on my old system, but it was with one VGA and one DVI port.

So I think the issue is that if you're running two monitors off one card, both using DVI but at different resolutions/refresh rates then you get the flickers.

To try solving this I'm going to add a cheap second card for the second monitor.

It really shouldn't matter. That card has dual DACs and should be able to run each monitor at different resolutions and refresh rates.

 

[CatMoon]

I agree that it should be able to but at some level there's a flaw with it, but only under that specific circumstance.

I found a thread with others with the same issue but they'd never worked out what was causing it: http://www.hardforum.com/showthread.php?p=1030620150