Antec Three Hundred Black ATX Mid Tower Computer Case - Retail BIOSTAR TForce TP43D2A7 LGA 775 Intel P43 ATX Intel Motherboard - Retail VisionTek 900244 Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor OCZ Platinum Revision 2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model OCZ2P800R22GK - Retail CORSAIR CMPSU-750TX 750W ATX12V / EPS12V Power Supply - Retail Item #: N82E16817139006 All of the above as well as a new 500GB SATA HD and a fresh copy of windows home premium. When I first fired up the computer I worked for a couple of minutes and then the computer shut itself down. It wouldn't power back on at all. If I unplug the power supply and plug it back in and turn it on the computer turns on only long enough for the motherboard LEDs to flash on and then it shuts itself off again.:bang: I'm far from a genious when it comes to troubleshooting, all I could figure is maybe the motherboard is defective. I'm coming here for helping hoping someone from this GREAT community can help me out a bit. Thanks in advance!