I changed my PSU on my Dell Dimension 8300 to a Antech 350W. Along the way I tried to put the mobo in a different case that came with a PSU, in the process removing the CPU. I'm new to all this so I dont know if I majorly screwed up or what, but since that didn't work, I put everything back in the Dell box, returned the case, bought the PSU, stuck it in the dell, (with a little modification of the case so the outlet could be accessable) and then tried to power up. Nothin, nada. I thought I may have not seated the CPU properly so as I hit the power button I applied a little pressure to the heat sink, and the fans started sputtering and I heard a few nasty beeps before it stopped altogether. Now its as before, except nothing will stimulate that little response. Please, any help or ideas would be greatly appreciated, I don't need a dead computer right now, no money to replace it (just spent more than I could afford on the video card and PSU).