I'm having trouble with my new GPU (R9 280x). Long story short. Last month I bought the GPU, but couldn't use it because I had a shitty PSU. So today I bought a new PSU (Antec High Current Gamer 750w) and I connected the new GPU. First boot is ok, used to have catalyst, so no big deal about drivers. But when I opened a game it crashed before it even started.
Then I restarted the PC, but I couldn't boot past windows 8 logo. When Windows 8 user password screen should come, my screens starts blinking.
I tried using the onboard gpu, and everything is fine. Tried uninstalling AMD drivers, but got same results. Don't know what else to try!