Question : Problem: No power after installing new motherboard and CPU.

I just installed a MSI K9A2GM-FIH Motherboard and an AMD Phenom X4 9750 CPU. When I applied power nothing at all happed no fans, no video no signs of life at all. I removed the memory disconnect all drives etc did every thing I could find here to trouble shoot. Nothing made a difference it was still as dead as a door nail. I then removed the ATX 12v power connector (I believe this powers the CPU) and when I applied power the fans worked and there was power to the hard drive and cd drive, but no video not even a flicker. When I reconnect the ATX power connector everything was dead again. FYI, I have a 600 Watt ATX power supply with a 24-pin power connector.

Phil

Answer : Problem: No power after installing new motherboard and CPU.

i suggest testing with the minimum setup - disconnect also all peripherals and network cables :
motherboard + cpu + 1 ram stick, video card, power supply
on boot, do you have a display?
if NO it is one of the connected, swap ram, Power supply, video card - leaving only motherboard and cpu
if Yes, add devices till the problem shows