Build computer not turning on.

Hey, guys. I just rebuilt inside a new case. The problem I'm having is that when I turn it on, the green LEDs on my mobo come on for a split second, then turn off. No fans start. Nothing. The OC button, Start, and Reset button on the mobo all stay on, but nothing else.
The build components are:
Asus RoG Crosshair V mobo
Cooler Master V8 heatsink
ATI Radeon 6950 GPU
16gb Corsair XMS3 DDR3 1333 RAM (4x4)
1350 watt PSU EarthLink or something around that brand.
Antec DF-35 Case
120 GB Intel 320 series SSD
1TB Western Digital 7200 rpm HDD
Some random disk drive

All the power cables to the mobo are plugged in. The only cable I'm honestly not entirely sure about is a three pin from the PSU to the mobo. It had a spot, so i plugged it in. Any help would be useful at this point.
16 answers Last reply Best Answer
More about build computer turning
  1. a 3 pin from the psu to the mb? Not likely

    Follow the advice in the thread at the top of the forum about how to troubleshoot
  2. As weird as it seems, there's a random 3 pin coming from my PSU. And at the top end of my mobo is a 3 pin spot. I'll reread those, though and see if anything catches my eye this time.
  3. There are only two power connectors on a motherboard

    24 pin main connector

    4 [ or 8] pin cpu power connector
  4. MBs usually have pretty good instructions on how to set them up. I bet you plugged your 3-pin power in fan pins. Also some MBs don't start without having plugged in your CPUs fan ( check that you've plugged it in the right place ).
  5. Not on the Crosshair V. There's a 24, 8, and Mullocks. All of which are plugged in. Even with that random 3 pin out, it doesn't work.

    I forgot this in my original post, but when i power on, I get a high pitched charge up sound before the LEDs go off.
  6. CPU fan is in the correct spot and plugged in. That was one of the first things I do when building otherwise I find myself forgetting and assuming I had done it.
  7. There are only two power connectors on a motherboard

    24 pin main connector

    4 [ or 8] pin cpu power connector

    and interestingly enough when I check the spec's for your mb thats the power connectors it lists .
    Possibly you fried your mb

    read the instructions next time
  8. The Mullocks is in the manual. But, okay. It did the same thing without the Mullocks plugged in before, because I thought that was weird. This isn't my first walk through the park. I came here for possibly something I didn't think of. Not to be talked down to. Next time, I won't bother. Thanks for.making me feel unwelcome.
  9. You're welcome
  10. Just checked the manual, and there are 4 power connectors, the 24 pin (in the usual spot), the 8 pin (top left), a 4 pin (top centerish), and the molex you've mentioned. Have you missed that 4 pin at the top? (given you didn't mention it earlier)
  11. Yeah, that's the one I always do first.
  12. Best answer
    If you have a run through :

    and post back how you get on (if you've done that, you can try breadboarding, ie out of the case, installing one step at a time)
  13. The molex is not a power INPUT

    The board should boot with either the 4 pin , or the 8 pin or both the 4 and 8 pin power connectors
  14. Afraid it is a power input. It may not be needed (given that in this case there's no SLI), but that shouldn't mean the board is screwed by having it connected (though maybe the 3 pin has caused damage, i'd rather test and make sure before binning the mobo).
  15. Definitely forgot to post that that solved it. My PSU just decided to die, which is fine because it was terrible anyway. Thank you, Mark_F.
  16. Best answer selected by Socratic.
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