My daughters computer which I built years ago and has been running fine froze when she was playing a game, she says she could not reboot it and could only switch it off by cutting the power at the back, since than the computer boots like normal but wont post the bios and left with a blank screen. Have done the obvious cmos reset with battery out and tryed a different graphics card to no avail. I installed a new motherboard battery a few weeks ago because it kept loosing the date and time but has since been fine but i'm thinking it has to be the motherboard. Motherboard is the Asus P4P800 deluxe. Thanks for any help.