from my experience, the powersupply probably blew something. see if you can get another one around or above your current powersupply wattage and test it on your machine. Try testing it with just the power to the motherboard / video cards hooked up.
If it still doesn't want to boot, reset bios and take out the battery for 5mins. then put it back in and start the computer.
if that doesn't work, then maybe the board / ram