My mates computer has had this problem with his PSU for sometime.
The problem is (if you didnt already know) that the computer will turn off but will not turn back on , to make it turn back on you have to reset the powersupply (turn off the switch on the back and wait 5 seconds )
Today we unplugged the Video card , Fans , APIC is enabled and we are unsure about what to do , any help will be truefully apriciated
8800 GTS
Fujitsu siemens - G3IT -M2
2GB DDR2 800hz Ram
500gb HDD
OCZ 700 MODXSTREAM Pro
PSU Is stonecold .....
9 Fans - 1 x 200 mm 7 x 120mm and a CPU fan
First possibility is there's something wrong with the PSU. If you have a working one handy, I'd test it with that. Next possibility is something is fried on your motherboard. blown capacitors or scorch marks are pretty easy to spot, so if those aren't there, it's probably not that. Lastly, why do you need 8 fans in a PC? I've seen 4U servers with fewer fans than that.
There doesnt seem to be any scorch marks but I will take another look - as to another PSU Ill see if I have one handy and see if that makes a difference
I would eliminate the RAM as the cause of the problem before replacing the motherboard. Try setting the RAM speed/timings/voltage to the recommended settings in the BIOS, then run Memtest86+ overnight to test for RAM errors. You could also try each stick of RAM by itself in the first RAM slot.