System powers off with CPU in

[smiffer]

Parts: Intel Core 2 Duo E4400, Asus P5K-V mobo and Asus P5N-E mobo

I'm building two systems and started on the first this morning. I powered the system on for the first time after connecting everything and the fans (cpu & case) would spin for a second then no power, like I hit the pwoer button then unplugged the power cord. So I first tried a different PSU, same problem. So I went back to the original PSU, unplugged all HD's and fans from the motherboard, same problem. I removed both sticks of RAM, same problem. I removed the board from the case and set it on the static wrap thinking there might be a short, same problem. I then removed the CPU and plugged the CPU fan in, hit the power button and power stayed on. What the heck. I inserted the CPU again and hit the power switch, same prolem, CPU fan would spin for a second then nothing. Thinking the CPU may be bad I opened the other CPU and inserted it but unfortunately same power loss prolem. OK so now I'm thinking it's the motherboard. So I open the other motherboard and put the original CPU in it and have the same problem. This makes no sense.

 

[sink]

It might not be your internal hardware. Did you try using a different power cable and plugging it into a different socket?