long story short computer wont turn on

[napalm]

ok

video card fried so i had to buy a new one. this means i had to build a whole new system. Agp to pci express.
got new chip amd am2 4200
new motherboard gigabyte ga m57-s4
new graphics card ati x1900xtx crossfire. 512.
2 new pieces of ram. ddr2 512 x 2

i put it all together carefully. once i pluged it in the power supply turned on (without pushing the power switch). all the fans and lights worked but no signal from the screen. The psu was making a strange sound. it was flashing and one of the two fans wasnt working. The power button wouldnt work either.
got a 580 w type r power supply. one of the best on the market.
i quickly decided that this was the problem.

i replaced this with another identical psu. The computer booted up!

i had to replace it with a third identical psu. Long Story.
then the computer didnt turn on. The light on the back is showing that the psu is getting power.

i then replaced that psu with the psu that made it turn on and now it doesnt work.
the two new identical power supplys have been checked in other computers and they work.

i went back to my original psu that showed some lights and didnt turn on the screen and it is still giving power to the motherboard.

i plugged in one of the new psu s and i accidentally pulled the power cable from the motherboard (half way) suddenly i am getting life.
the psu is lighting up but the computer still wont turn on.
the new psu is now acting like the 1st psu. but if i plug it in fully it turns off.

sorry about the complicated story.

any ideas.

thanks.

[Tyler]

Interesting, are you sure you plugged in your graphics card and all your components to the right power lines? I would double check that. Other than that I'm not sure, I would just go the trial and error route, try the motherboard etc.