I turn my computer on, and all the fans run. I've narrowed down the hardware problems to the CPU and Motherboard. I ordered a new motherboard, the same model, except slightly better, ASrock K7VT4A+ to K7VT4A PRO. I was using AMD XP 2400+ and put the chip in the new motheboard, and the system still fails to boot. I'm not sure what to do next. I am debating weather or not to send the motherboard back for a new one. I ordered a new CPU, the same one as before.
Should I keep this motherboard, and try the new chip in it, or should I send it back requesting a new old one (K7VT4A+) or is the new CPU going to short out if the new motherboard is shorted out as well?

I just recently replaced the power supply from a 250volt to a 580volt, system worked for quite some time before this happened.

Motherboards are very sensitive to things like getting rammed with twice the voltage they were made to handle. The 580v setting is for europeans, and fortunately we are not european, if you switch the power supply back over to 250v the computer should work again. Chances are you didn't short out the motherboard or the CPU. But, since you just purchased an upgraded motherboard and CPU why not use them.