i had a really similiar problem milla a few years ago. turned on pc in the morning, was frozen. rebooted, woulndt post. tried new cpu, worked fine. but i tried the new cpu after i replaced the motherboard and powersupply. i had a new motherboard i bought anyway so i just put it in then to see if that would fix it. didnt, so then i tried a diff cpu at my dads work and it worked fine.