has your mobo go on board graphics if so take out the graphics card and unplug any other unnecessary parts, if it posts then try putting everything back in one at a time and keep testing until it wont post and by then you will have your culprit
yes, the beeping magically fixed itself somehow (maybe the pinholders were dirty)
and i tested the gpu on a system that i have standing here (wich i-am not even sure if it works... ;( ) but no screen so or that system doesnt work either or it is the gpu.