New custom not booting! HELP!

[DigitalSoul]

I just got all new parts to build my computer and when I hooked everything up it will not boot. Here is what happens, the monitor doesn't show anything, the LED on the motherboard(Soyo kt600) is showing green but none of my fans run, none of my hardware run(hdd, cd, fdd, none will run!), and my proccessor heatsink/fan (2.8 athlon xp barton) isn't running either! The only thing that seems to be working are some ports on the back panel such as the keyboard, mouse, and USB, also the LED on the mobo is showing. When I turn off the power it gives one long *beep* and my Vpu heatsink/fan runs for like one second and thats it! I tried the cmos reset, I tried setting up the mobo out of the case, I tried switching the memory around, i feel like i tried everything! Please I need assistance from you more experienced people! This is really frustrating for me, I do not know what is wrong and it seems like it could be anything, maybe something is defected (I suspect RAM). Please help me...

Here are the rest of my pheripherals:

Athlon Xp Barton 2800+
Ati Radeon 9800 AIW
Bayone AVI plus
Cdrw 52x32x52x
Dvd rom 16x
Seagate 120 Gig hdd
Floppy drive
Soyo Dragon Kt600 platinum
Soundblaster Live Gamer
Coolmax 550w Taurus
Mushkin 256x2 pc2700
Chieftec fulltower Dragon Case

I'd really appreciate some suggestions on what to do, thank you!

[cbuddha42]

test the psu........disconnect it from everything then hook up one fan and do the paper clip trick.........tell us what that gets you

[DigitalSoul]

Well, I got it to boot in a strange way. While I was sitting around helpless playing around with the components, I started fiddling around with the 20pin ATX power connector, I inserted it slowly and the fans started spinning for 2 seconds and stopped, so I played around with it somemore(kind of like hotwiring a car!) and it booted... Although I am still not satisfied because everytime I do a cold boot I have to do the whole process all over again (fiddeling with the ATX 20pin m/b connector) until the cpu fans start spinning etc. I want to find a solution for this so I can just turn it on by pressing the switch on the PSU, Although I don't know which is faulty, it's either the PSU ATX 20pin connector which has a convertor for 24pin to 20pin(Although on a PSU tester it seems fine...), or the mobo's connector. Do they sell those convertors anywhere?(m/b ATX power connector 24pin to 20pin.) For now I guess I just have to avoid cold boots...