The beeps could signal any number of problems. Did you unplug and reseat your RAM, video card and any other plug in cards? Are there any signs of fried components or electrolytic capacitors that are bulging (domed) at the top?
What is the beep sequence? That is, how many long or short beeps? Check the motherboard manufacturer's site to find out what the beep code means.
Good luck. 🙂