[CaptStirfry]

I've been trying to fix this problem for ages now, I have no idea what is causing it. When I play a game in full-screen, it will just show black. Sometimes the sound plays sometimes it doesn't. Sometimes I can alt tab out and alt tab in, but this is an extremely rare case. When I play a video from Vimeo or Youtube, and if there is a part where it is black, it will not come back from it. It will stay black and lock up my system. Same thing happens when I try to play a video in Windows Media player or VLC. When I try to reformat, and I boot from a CD, all I get is a black screen. I've upgraded the drivers, but that didn't help. I've reformatted, but the problem still persists.

Windows 7 Professional 64-bit.
Mobo: Gigabyte GA-MA790X-UD4P
Processor: AMD Phenom II X4 955 3.2GHz
Memory: 6 gigs
Display: Nvidia GeForce 9800 GTX
Moniter: LG W2241

[Triple6]

What is the make and model of your power supply?

Also download and run HW Monitor: http://www.cpuid.com/hwmonitor.php
Please play a video for a bit and then take a screenshot of HW Monitor and attach it here.

[CaptStirfry]

PSU: OCZ GAMEXSTREAM 850W POWER SUPPLY

[CaptStirfry]

My suspicion is that it's the monitor, and that's to bad, as the only solution to that is getting a new one.

[Triple6]

If you think the system locks up the its not likely the monitor. I'd be leaning toward a video card, motherboard problem.

Also what BIOS version do you have? You need at least F4 for the Phenom II X4 955 C2 revision but you need F8 for the C3 revision.

Trying, borrowing, another monitor will give you the answer really quickly though. LG also has a 3 year warranty if it is faulty.

[CaptStirfry]

I do not believe it is the motherboard, my old one fried and I had to change it out; the problem persisted even after this. It could just be the graphics card and its broken, but I don't understand that if it was broken, how would I be able to play windowed games? Why would it just be that only full screen things don't work?

The system doesn't really lock up. I still get sound from the games, and I can alt tab out, or force quit, and the sound stops, but the screen remains black. The only solution is to restart the computer.

I will check the BIOS now.

[Triple6]

Well again I would recommend you borrow a monitor from a friend and test it.