I'm at a loss to explain this one. I have a refurbished Samsung 24" monitor that, when connected to my desktop via DVI, seems to be crashing the computer. At the very least, it seems to be crashing the display driver, which has caused 2 BSODs. It also has been frequently blanking the screen (flashing black then back on).
Unfortunately the computer itself isn't free and clear of all wrong-doing here, either. It has an ASRock A790GXH/128M motherboard and I'm using the on-board video. I've had this system about 8 months, and it has had its issues. The ATI drivers for the motherboard and video have never upgrade themselves cleanly – I always have to do a command-line uninstall and new install. Twice the on-board audio has gone out for no apparent reason – both times were fixed with driver updates. It had been working fine, but I just did a reinstall of Windows 7 and these issues started happening.
Here's the kicker – I hooked up an older LCD to the computer using VGA and it hasn't showed any of the issues! I think on the AMD790GX chipset the audio and video are on the same silicon, so it very well could be the computer. It just seems like if it were the computer it would show the same issues using VGA. This is what leads me to wonder if a defective monitor could cause these kinds of issues.
Update: I'm currently using the 9.11 ATI Catalyst drivers. I have both the SouthBridge and Display drivers installed (no Catalyst Control Panel).
Update 2: OK, the ATI display driver just crashed using a different monitor connected using VGA. I'm leaning towards bad motherboard?
Best Answer
I think its the monitor and associated driver combination that are giving you trouble.
Is it possible to try booting your pc with a Ubuntu LiveCD?
You may need to get the ATI drivers for Ubuntu to get it all working... but it should help diagnose your problem.
If you get your hardware working with the Ubuntu LiveCD it proves the hardware is good. You then need to focus on the Windows 7 software.
One other way to check your hardware is to get a DVI-to-VGA adapter and connect your working VGA monitor over the DVI path. Getting the adapter may not be easy, but if it works out for you, and the VGA works on that path, you can also rule out the DVI adapter as the problem (but i think getting Ubuntu to work might be a tad easier than acquiring this adapter for the testing).