Hello everybody! 3 weeks ago i bought GPU Sapphire RX 580 in local store (as i understood - GPU was used, because it was with a discount, but they gave me 4 weeks varranty). Today, when i was playing Dota 2 and Whither 3 my screen two times give me error: no VGA signal. But computer still was working, just screen had this problem. Reboot solved the problem. What do you think, which kind of problem is it? Is it really GPU? Or maybe because of my old xeon e5450? Or power supply? I will be thank you for answer!