This Is Very Wierd. My Computer Has Been Working Great. I Was Out Of Town And I Came Back And Powered On The Computer It Starts To Boot Up Normally But After 4 Seconds If Completly Dies Down. All The Leds Lightup Like A Normal Boot. I Thought It Was The Motherboard Because I Took The Same Power Supply And Put It On Another Computer And It Worked Fine. So I Bought A New Motherboard And I Reconnected Everything. Still The Same Problem. After 4 Seconds It Shuts Off What Could Be Wrong!!!!!!!!
Someone Help!!!!!!!!!

Could it be possible that it is overheating? Check the heatsink's fan on the processor, make sure it is running.