Ya i had this build running solid for 3 years. Recently purchased a h105 corsair cpu cooler. This problem arose when i was overlocking.my temps were around 60c on full load and voltage at 1.38 this was with a 4.6 ghz overclock. Soon as i pushed a 4.7 with 1.4 that when hell broke loose. Pc locked up. I reboot then the cpu led came on. Ive gottne the pc to post and function a couple times.
Another thing i might add is i e tested my ram with memtest and it checked out ok. Also when cpu led was on my gpu would have no fans spinning, power and reset buttons did not work and cpu cooler fans, case fans, psu and it fan, mobo power light all on.