One works fine. The other had some issues connecting recently and would work for a day at a time and then stop working. I figured out it was because the bracket that sits against the case that you put a screw into to seat the card tightly was slightly bent. I bent it back into a straight position and the card connected without an issue as predicted. Five minutes later I got a blue screen and the card didn't work when the PC rebooted.
So I went through the checklist of taking out and putting in cards blah blah blah. Then I took out the working card and put the nonworking card into the working card's slot. Booted it up with ONLY the faulty card. WORKS! I get to windows login screen, screen goes black.
Looked up the issue, people say they can boot into safe mode because it might be a driver issue. Tried that, doesn't work.
Went into Bios, screen goes black after a bit of time.
I started timing how long the card would work. Averages about 10-15 seconds.
I have updated the driver to latest (non beta) edition but no difference.
Did have a Windows update recently but the fact that the card stops working after 10-15 seconds whether I'm at Windows login screen, in safe mode, in the BIOS, or Boot first options, rules out that Windows is behind this issue.