Computer doesn't detect monitor/keyboard

[TinStar]

The only thing that has changed was a few months ago I switched out video cards (the old one was from like 2004). I was having issues during seiges in what I deemed to be possible overheating because both of my monitors would go black but I could tell everything was running in the background because I could still talk on TS. I just wouldn't think that would screw with the keyboard as it can't draw much from the power supply right?