I had a bunch of spare parts left over from a AMD 3400 build I did a while ago, and decided to put them in a new case and use it as a spare pc or whatever. I put it together and when I turn it on and hit the power button it lights up for a second and I hear the fans start to spin and it shuts off right away. It doesn't stay on long enough to get to the post screen, just stays on for about 1 second and shuts off. If you hit it again it just does the same thing. All connectors inside I'm pretty sure I have correct, this is the 3rd PC I put together and I haven't had a problem like this one before.
I reused all the same stuff that had been together in another case, power supply, mobo etc that had been working together fine a few weeks ago when I took it a part. The only things different are an older CDR drive instead of a DVD drive and I didn't have a spare floppy so I didn't put one in yet.

I would look for a short. You might try unplugging everything except the CPU HSF, RAM and Video card and trying to get to BIOS that way. If not, your MB may be shorting out to the case and would need to be reinstalled properly.

tried unplugging stuff but it didn't help, in fect it wouldn't do anything. I tired putting evreything back and now it won't even flash the power light like it did before....does nothing.

If you unplug everything except the CPU/HSF, Memory and video card (unplug all optical drives, hard drives, PCI cards, sound cards. floppys, case fans, everything...) and the system will not boot into BIOS you will have to take the MB out of the case and build it on a table outside the case and try with only RAM, CPU and Video card. Your only other option is to try reseating the RAM and Video card. And also you can try resetting the CMOS jumper. HTH.

Maybe you have a heat problem and your PC Shut off Because the CPU temps are Very High

Did you put the case standoffs before putting motherboard? if not, motherboard is touching case tray metal, and this makes it shutdown immediately.

yes the 9 screw in stands are in there properly. I guess I'll try it out of the case. So should I leave the hard drive unhooked too just to see if it will get to the post screen?

Well I took it of the case and hooked it all up with the power supply still in the case. It booted up no problems. So the problem I guess is with the board or something shorting to the case, but I can't see or figure out what the problem could be. Any ideas on common places for this to happen? Thanks again.

You might try reviewing this document. Good info. http://www.tomswiki.com/page/Troub [...] ild?t=anon

even a P4 Prescott cant get that hot that quick

Well I got it running, it seems the screws I used to hold down the motherboard wern't the right ones, these had a rather large head on them that may have shorted something on the printed circuit of the board. I used some smaller ones and it booted up OK. Thanks for the help.

Good to hear you got it running. Persistence prevailed in your case.