Question : Problem: Black screen in some games

hi.

PC specs:

CPU : E6850 core 2 duo
GFX: 9800gx2
Ram 2gb @ 800mhz
PSU 800w

I have had this machine for 1.5years with no problems. I have changed nothing recently.
Over the last week or so, I have been experiencing sudden black screens in the middle of graphic intensive games, such as Black & White 2 and Dark Messiah of MIght and Magic and once (I think, as it happened overnight) with no game running at all.

When this happens, the monitor display reports a "No Signal Message" and I have to restart the pc. When I get this black screen  I can still hear some game sounds for a few seconds and the pc is still going, power wise. After a short while, the game sounds die but the again pc is still going ( lights are on and fans turning etc.)

I did suspect the gfx card overheating but I do use riva tuner and so have the gfx card fan spinning at maximum speed. It also has its own dedicated fan in the pci slot beneath it. Also, this wouldnt account for it happening just recently when ive playing far more recent graphic intensive games on max settings all through last year. (Oblivion, Fallout 3 etc)

I wondered if the issue was with just one game but as its happening in two now, this doesnt seem likely. I do recall leaving it on overnight without any game running and getting up the next morning to find a black screen.  I also tried rolling back the gfx driver and reinstalling both games (both patched) I also reinstalled directX 9.0c directly from microsoft.

I have also checked all the wires and connections and they are firm and secure. The monitor is also fairly new (Samsung T220HD) My system is not overclocked.

Is my gfx card just dying on me?  

Answer : Problem: Black screen in some games

>>Is my gfx card just dying on me?

Possibly but also it could just be overheating (or underpowered - see later). You've already checked the software based performance indicators but make sure that also looks like what is happening inside the case ie the fan is actually moving not reporting that it is moving.

Also make sure you don't have dust building up on the card or around the air passages through the case. As you have a dedicated fan I guess you have already covered this.

Another component you should put on your list of suspects is the PSU. Do you have another power supply you could use (or even plug a second PSU in just to power the GPU with the case side off as a diagnostic test)

How quickly can you get back into the system after such a crash? What are the GPU stats after that?
Is you 9800 overcloacked - which make of card is it?