So I bought a 5870 off my friend for cheap, but he says it had some minor issues. Frame drops and such, but just in one particular game. I just got it today and ran it through the OCCT: GPU torture machine to see what's what. It ran strong for about 15 minutes or so, no errors... then, no video. I ran this test once before today while I was away and I came back to no video, but the fan was still screaming. My guess is, the test was still running all that time (because of the fan speed), but I just wasn't getting any video. What could cause a card to suddenly output no video like that?