Alright, i have an old computer that i took apart to make a new one, now i want to go back and start the old one but for some reason it only turns on when i plug into the wall and it turns on for like 4 seconds and then it turns off, and hittin the power on switch button wont work, i have to unplug it from the wall again, wait a few seconds then plug it back, then it will turhn on for another 4 seconds and then turn off and this will continue all day long. Specs of old motherboard: GA-71XE AMD 751/756 chipset/ Amd Athlon 600mhz Slot A\266MB RAM, 30GB HD\CDRW 24x4x24x\SB LIVE\3D annihilator Geforce 2. any have any idea what could be the prob? PSU 300 Watts. the computer use to work fine until i move the Hard drive, soundcard, and video card..and since i got a newer, bigger HD, and better Sound card and Video card, i put the old one back and tried to get it runnin and ...well ya'll know what happens. if anyone could have an idea on how to help me wit this issue it would be great help. thanx.