Mx45 u2-cn motherboard

you meen MX46 U2-CN this board does not support fsb533 only 400MHz will works on it.

Your not getting any video at boot up? I would be looking at your video card first. Remove & reinstall. Than try again to enter bios. Still no? Reset the bios on the motherboard. You'll have to remove the battery & check it for 3volt. Replace, got video enough to enter bios? Disconnect all non needed items. Like diconnect CD/DVD rom drives power cable & data cable. Got two Hard drives. Connect only one. Two banks of dimms. Use only one. 1PS2 mouse & keyboard. Try boot up again. Listen for post beep. (1 beep). Any other beeps, count how many and if long or short. Let me know. Lastly did you apply thermal grease between the cpu & heatsink?. The idea here is to get down to basic needs only. If it were your cpu it wouldn't even power up. Than again every board is a bit differant. Give this all a try & poat back. Good luck!