No matter what I'm doing on my PC (games, internet, etc) my monitor will randomly lose signal but my pc will still be on. The monitor will come back on when I reboot the system however. I am getting normal temps for my GPU and CPU. Also, I just built this computer a few days ago and the parts are brand new. I have a 600 W power supply and its more than enough for this build. My gpu is a 5700 series and i currently have the latest catalyst drivers in Windows 7.