PC Powers up, turns off and then powers on... nothing?

[HAVOC]

^ sounds likely. all though my board supports P4's and that is a DDR3 P45 board. so i dont know. try resetting the CMOS.

Your board probably supports P4's based on it's BIOS.
EDIT:
(Yes, I was correct about your board)
F5 2009/02/24 Enhanced compatibilities of Dynamic Energy Saver Advanced
F4 2009/01/13 Support ITE8718 KX
F3 2008/11/14 Support raid HDD up to above 2000GB size
F2 2008/11/03 Update CPU microcode(Support Pentium 4/Celeron CPU)
F1 2008/10/13 First Release

He could easily find out by using the link I supplied for him for Foxconn support.

 

[Nagasama]

check the voltage.