Sx 2803 gateway motherboard which one?

If the board is fried, and your system is out of warranty, then use a g43 chipset board with onboard video like this: http://www.ascendtech.us/itemdesc.asp?ic=MB4ECSG43TMV10... This is an inexpensive board that will do all your system needs, and even has an hdmi port for blueray playback. This board is not designed for high performance if overclocking is your goal. And you may have to get a new windows coa, as your original installation is normally tied to the original gateway board.