This is a custom machine that had been working for years for my friend. He said it froze and he unplugged and replugged it into the wall outlet a few times. After that he called me.
The machine has no PCI, Video or any other cards in it. Just the Motherboard, CPU, Heatsink/fan, and memory stick. (I unplugged the SATA Hard Disk). It has Video on the Motherboard.
It just plain will not POST any more. I first replaced the Power Supply...no POST. Second, I replaced the Motherboard (Intel D915GAG) with a new D915GAG motherboard and the original CPU (P4 3.0GHz)....still no POST. Third, I replaced the CPU with a P4 2.8GHz....still no POST. I tried replacing the memory with no luck. I connected a old IDE Hard disk but it does not spin-up when the power is turned on....Why is that?
Interestingly, the "Standby Power LED" on both the new and old motherboard is lit when the power is turned on indicating that at least some power is getting to the motherboard.
I am at a loss as to what else to try. Any ideas?