HELP: Built new computer and can't get it to turn on

[n_md]

So i went out to frys and bought a case with a 420w power supply and a bunch of fans, a AMD 64 3000+ cpu, Gforce 6800 oc grfx card, a 80GB hard drive, a CD-RW drive, 1GB of DDR PC3200 400MHz Patroit RAM, and a MSI K8N Neo mother board

K8N Neo-FSR mobo link:
http://www.msicomputer.com/product/p...o-FSR&class=mb

Gforce 6800 oc grfx card link:
http://www.bfgtech.com/6800OC.html

i got it all set up in the case and followed all the instructions and such but when i trun it on everything starts for a second and then it just shuts off... the mobo was a reduced price because it had a sticker saying it could have been used or repared and there was the plastic wrapper with a Shrek DVD price tag on it and 3 bent bits of metal from someones case inside the mobo box which was a bit worrying but the mobo its self looked new and perfect

i've tryed many different things to fix the problem:

disconnecting the power supply form any unimportant fans and lights

trying to turn it on with and with out cd and hard drives

switching out the ram from my old computer

switching out the grfx card from my old computer

running it mounted in and out of the case

tryed running it with nothing but one stick of ram and video card

i've tryed unpluging everything and repluging it

i've cleared the cmos

i removed and then replaced the heat sink and cpu which both were already in properly


if anybody has any ideas for me to try plz post them i really need to get this running

thanks!

heres some pics of makeing it:

https://home.comcast.net/~dunnedm/comp.jpg
https://home.comcast.net/~dunnedm/comp2.jpg
https://home.comcast.net/~dunnedm/comp3.jpg

[LeftCoast]

Personally, I'd consider bringing the mobo back DOA.

I try to stay away from recertified mobos, as there are too many things that can go wrong with them, and I would just prefer such a critical part be new.

[MitaDC]

2 quick ideas: take and remove the mobo out of the case, or atleast make sure it isn't grounding on anything, 2nd take a flathead screw driver and short the 2 pins to turn on the computer and see if that works. That is to check to make sure that the power switch isn't sticking...

[mazdarx7-64]

Also make sure that the PSU is good. Make sure that the PSU is on 115V not 220V, if your in the US.