No power to board

I am attempting to build my first system. I have swapped out most parts before, just never actually built one from scratch.

Anyways, my problem is that when I hit the power switch on the case, the power on indicator light flashes then goes off. The fan and none of the components on the board seem to have power.

I am using a Gigabyte 965P DS3 mother board, 2 GB DDR2 800 G.Skill memory. E6600 chip, CompUsa(I know, I know) 500W power supply and case, Evga7600GT. 2 320GB SATA HD's.

Let me give some background. After powering it up the first time I didn't really do anything special in the BIOS, I just left everything standard. it seemed to start up, showed the Gigabyte splash screen, then continued on to displaying the components, then finally gave an error that I had no OS. No problem so far. Then as I was looking for my OS, the power indicator and DVD lights on the cases started flashing and I wasn't able to reset it or anything. I shut the power supply off, thought maybe I put the reset switch in backwards and reversed that. Started it up again and waited a few minutes, it stuck on the OS again, which is to be expected. After giving it five minutes I stuck my XP dist into the drive and it started loading XP. while it was loading the OS, the computer shut down.

After that point I was not able to get any power to the board as far as I could tell. I bought a PS tester and tested the PS and it showed as being bad. I had another 500W power supply that came with the case and so I tested that and it showed okay. I plugged that PS in, then attempted to start the computer and the power indicator light flashes then everything goes silent. One thing I noticed is that if I disconnect the ATX 12V power plug then attempt to start it the CPU fan comes on, the front power indicator light comes and things seem to come on, however, the monitor never displays anything. I have tried clearing the CMOS by shorting the two prongs discussed in the manual and that doesn't seem to do anything.

So at this point I am wondering what the different things are that could be the problem, I am leaning towards the MB dieing as a result of the first bad powersupply, or maybe it had a problem anyways and that caused the problem with the first power supply.

Any help would be appreciated.
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  1. A little bit of a follow up, I have taken the mobo out of the case, placed it on the mobo box, plugged in the memory, video card and power. Then turned the PS on and shorted the power on jumpers. When I do this with both the 24 PIN power connecter and the 4-pin ATX-12V plugged in nothing happens. When I unplug the 4-pin 12V ATX plug then the fan for the CPU spins for a few seconds.
  2. Frequently when the machine starts and then shuts down it's an overheating problem. Do you have th HSF plugged into the correct connection on the board? Also, have you tried reinstalling the CPU? If not, I'd clean all the thermal paste off of it and replay a fresh.
  3. I had a very similar problem to yours last weekend. One day, my mobo's power light and LED would light up for a split second after hitting ON, and then would shut off. After hours or troubleshooting, I still couldn't narrow the problem down as all of my components seemed to run fine individually on another PC. I even went so far as ordering nearly all new parts (RAM, mobo, CPU, PSU), but even after replacing I was still experiencing the (no)power problem.

    Finally after using my symptoms to research online it seemed as if I had a short somewhere in the system. Since I had already eliminated most of my components as the culprit, I started unplugging the ones I hadn't checked. The very last one I checked (I was about to off myself at this point) were the cords to the USB/Firewire port on the top of my TT Armor. Sure enough everything powered-up and worked after that.

    Anyhoo, my point is you should consider all your components as suspects here, not the the usual ones. In my case it was a measly USB cord.
  4. Ensure the ATX 2x2 pin connector is in.
    Disable Qfan or whatever you have in the BIOS that can slow down the fan.
    Double check all connections.
    Go into BIOS and check Boot Order.
    Then reboot and listen for 1 short beep.
    Incidentally, the front Power and Reset switches can go either way onto the mobo, whereas the other front panel connectors can only work one way. See your mobo manual. If you haven't got it, download it. :)
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