Graphics card seems to have vanished

So interesting story. I own an Asus desktop model cg5275 with a radeon hd 5870 graphics card, an i5 intel processor, that runs on windows 7 home 64 bit.

So I started my computer up this morning and my monitor is blank. Computer seems to be running but there's no response from my screen (Asus 1080p if that helps) at all. So I hook up my ps3 to the moniter to see if its my screen and sure enough theres my ps3 home screen. I mess with the different ports that my card has swapping between my dvi slots before trying the hdmi. But it's no until i plug my monitor into my intel (r) graphics media accelerator hd (an integrated motherboard graphics card) that my screen finally gets a signal from my pc and I can at least snoop around. I get some a warning messege about how my drivers for my ati card are out of date and i need to either update them or go into my display options and enable my card, which seemed odd to me. So I update my drivers and tthe warning no longer pops up but my card still wont talk to my monitor. Or maybe my computer won't talk to it. But the thing that's really getting me is my radeon doesn't even appear in my device manager anymore.

Does this sound familiar or ring a bell with anyone? I'm not the most technical of computer guys and i've pretty much reached my skill limit.

I'm running two video cards SLI'd together. I connected to my monitor for about a year using HDMI and all was fine but then my monitor started going blank. Like you it said it wasn't receiving a signal. For awhile I could switch to a different port and it would connect but after awhile even that didn't work. I went back to using a VGA cable and it has worked fine ever since and if there's difference in the picture I can't tell. No one's been able to tell me why the HDMI has problems, but from my own experience and from what I've read it does. Try switching to a VGA cable and see if that fixes your problem.

Uninstall the drivers you have with that 5870, then run the newest Catayst Hotfix drivers after using driver sweeper. Disable any onboard GPU and ensure that you set PEG in your BIOS for the first card that boots up.

Unfortunately my card lacks a vga out I got 2 DIV's and an HDMI. I was kinda surpriesed actually. Anyway Ill start working on what you suggested cmd187. Hopefully I'll get this right.