THanks for the link evongugg but i don't it is the socket. I removed one of the chips and rebooted a dozen of times with overclocked settings and everything went fine so I don't think it is a socket issue. Than i replaced the chip with the other one in the same slot and after to reboots and intel burn tests the pc started playing one again. POST randomly stops and mobo ram light lights red. Might it be an issue of a defective chip ?