I am new to working on computers, and I have an eMachines T2895 2.8 Celeron D, 512DDR that fried the mobo. I got a replacement mobo and installed it. It booted up and ran fine but after 3 times hitting the power switch. After I shut it down, it will not boot now. When you press the power switch, the led will light but then the computer will immediately lose power. Then nothing if you press the power switch again (unless I unplug and replug the computer in). Sometimes the fan and LED will stay on for about 5 seconds before losing power. What could be causing this? Power supply? power switch?