Its a Dell Dimension 8300, 2.66 Ghz P4, 1 gig RAM. I just purchased a GeForce 6800, and since my machine only had a 250 Watt power supply, I decided to change it for a bigger one, as from what I read online it was standard ATX and replaceable. My problem started when rather than getting just a PSU, I got a case with a PSU installed. I thought my mobo was ATX, but it apparently wasnt as it didn't fit into the case. I had no intention of messing with it this much, but it was necessary to take the CPU off to get the mobo off its mounting plate. When it didn't fit, I put it all back together in the Dell case and took the new case back, in exchange for a new PSU. I come back, put in the PSU, and after all the connections are back together, it won't start up. Nothing, the only sign of life is the little green LED on the mobo. I go over all the connections to make sure nothing is missing or loose, nothing there. I thought perhaps the CPU wasnt seated all the way after putting it back on, apply a little pressure to it as I hit the power button and it makes a beeping noise for a couple seconds before stopping. I took out the CPU and reseated it, further causing problems when I noticed it didn't go in perfectly and some pins were bent. I spent many careful minutes getting everything back straight, and it now seems that it is seated properly, as it was before, I don't think that was the initial problem, though I may have damaged it in the process. Don't think so, but its a possibility. So, I read online that removin the PSU, taking out the battery, waiting 30 minutes, putting it back in, and plugging it all back together might do the trick in this type situation. I did this, and lo and behold, it worked. Fans spun up, power was obviously getting to places, but the power light on the front glowed amber instead of green, and no signal went to the screen. All the drives worked, but it obviously wasn't going through the startup process. I thought perhaps the video card wasnt seated properly, as this was what Dell recommended online when you get a solid amber light, and messed with that for a while. Then stupidly I thought again to reseat the CPU, thinking it wasnt all the way in, which I did, and it hasnt displayed a sign of life since.
I have both PSUs, both functional, both Video cards, but it doesnt seem anything obvious will now get it to turn on or exhibit any sign of life with any of them. The battery thing did not work the second time, so I'm stumped, pissed, and out of ideas. Thanks for the help, hope this gives you some idea or flash of insight, but I may be left just to take it somewhere to repair, or just get a whole new goddamned CPU, mobo and case....