Built Computer but will Not come on.

[grassxc]

Hey all I put my first computer together today and unfortunately it's not working. I hit the power switch and it turns on for a few seconds then immediately shuts off (doesn't reach POST). If I hit it several times the computer stays on but no POST/BIOS screen. I've swapped video cards and power supplies and got no change. I've taken out everything (except the cpu/heatsink) and get no beeps. Any ideas?

Rampage 2 extreme Motherboard
Core I7 950
Seagate 300GB HDD
radeon 5770 card
LiteON blue ray drive.

 

[grassxc]

The CPU is seated correctly and the heatsink/fan runs correctly

 

[JDFan]

Did you install the standoffs that keep the back of the MOBO from contacting the case correctly ? - sounds like it could be shorting due to the MOBO touching the metal of the case.

 

[grassxc]

I just checked it's seated correctly

 

[grassxc]

UPDATE : If I unplug the CPU power the motherboard will run everything or at least it runs all the fans (including the one on the videocard) However with the cpu power in it does the origional problem i.e. turns on for a few seconds. So my guess is it's either a motherboard or CPU any way to tell? Other than swapping the cpu with a working one or the cpu with a working MOBO (I don't have any spares)

 

[grassxc]

Update: A friend suggested there was to much thermal grease so i cleaned off the heatsink and processor and reapplied and got no change.