I have an old ecs p4m800 (an odd bird that used either ddr or ddr 2 memory) with a core 2 duo 1.86 pentium I thought I would resurrect for my grand neice. It would power up for 2 to 60 seconds, then shut down without getting to the bios. Once, the bios screen lit up and correctly identified the memory (I've tried several pairs of 1gb corsair and crucial ddr memory chips I've had lying around) though it pegged the memory speed at 400mhz instead of 675. I removed all the peripherals except for keyboard, mouse, and vga (on mb - I cleared the bios. I tried an AGP card. I put in a new power supply, Antec 400 watts. It's frustrating because it seems like its trying to boot, but then shuts itself off. Good fan, thermal goo. could be either motherboard or cpu but it seems odd that it almost booted one time. Any thoughts, before I plunk down a hundred on the new minimal mb/cpu compo?