Monitor turns black after about 30 seconds, no matter what

[iatelassie]

Oh boy.
I have a Dell XPS 400. Today I added a cooling system (accelero cooler rev 1.2) to my 9800gtx. In the process, I cleaned out the computer with canned air. I have installed the cooling system on 6800 gtx with no problems, and I was very hard on the old card. When I installed the cooler today, I used extra care.

I also attached an SLI cord to the monitor for the first time.

Then I went to boot up the system, and the monitor goes to sleep after 30 seconds--no matter what. I could be in BIOS, Safe Mode, or at the start up screen and the damn thing just goes to sleep. Maybe I hit something in the computer? Did I break the graphics card (I was seriously very careful)? What are the possibilities?

I have run the 9800gtx perfectly before this, no problems with the PSU or anything like that. So I'm wondering what I broke.


edit: these are things that I have tried so far:

going back to my original vga cable

going into safe mode and hitting "use last good configuration"

going into safe mode and going to "enable vga mode"--this is the first time I got through the password-entry process, and I actually saw my desktop for a few seconds before the monitor went to sleep. I

trying to start in safe mode

trying another monitor

No dice with anything.

=(

 

[mosox]

Hard to tell, maybe it's overheating. Did you just buy that cooler?

 

[iatelassie]

I had used it before on another card. It's totally passive tho, just a big heatsink. So the computer wouldn't even recognize it.