I've just built my new PC yesterday and what happened was the following: first attempt to boot only the PSU seemed to work (I could sense and hear the fan spinning). Second attempt also failed, but in the third the hole system turned on. I installed everything and played the entire night. Today I woke up and turned the PC on, used it and played for about 5 hours and now it turned off out off nowhere and wont boot again (Same situation, only PSU is on cause of the fan spinning). Another strange thing, my keyboard is a Cougar 200K and it lights up simply by connecting it on the PC with the PSU switch turned on.