New system won't POST, spent a good two hours trying to figure out why

So I recently built my own computer (second build, first build was for someone else), and after putting everything together and plugging everything in, I press the power button, all the fans turn on, the optical drive turns on, the LEDs on the motherboard turn on, but the computer won't POST.

I have done everything I can to troubleshoot without taking everything back apart.

-made sure everything was plugged in correctly

-made sure the RAM and GPU were pushed all the way in

-made sure no wires were running underneath the motherboard

And a few other things, so I'm just about ready to take it all back apart and try and do a breadboard, as well as see if the standoffs are installed correctly.

Which brings me to my question.

The CPU power connector on my PSU is for 8 pins, but it is split into 2 seperate 4-pin plugs. One of the plugs does not seem to match the pins it should connect to on the mobo (which needs an 8 pin plug). I'm suspicious that this may be part of the problem, so I was just wondering if anyone has encountered this sort of thing before? I'm sorry if I did a poor job explaining it, if you need me to elaborate just let me know. I would appreciate any kind of feedback before I basically start this whole build over again. Thanks!

-Intel i5 3570k cpu

-ASRock z77 extreme 4 mobo

-CORSAIR Enthusiast Series TX650 V2 650W ATX12V v2.31 PSU

-Corsair XMS3 8GB (2 x 4GB) DDR3-1600 Memory

-EVGA GeForce GTX 670 2GB Video Card
4 answers Last reply
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  1. I know of the two separate 4-pin plugs you speak of, which are most likely labeled with a "12V" stamp. I'm just now getting the final components in for a much similar build to yours but my PSU has the 8-pin supplemental power cord you're looking for.

    Looking at your PSU I don't see a 8-pin supplemental power cord, I only see the 4+4pin and the primary 20+4 pin.

    You might try referencing both the PSU manual & the mobo manual, maybe they will show which configuration of the plugs to use.

    It could be that you should use only one of the 4pin connectors from the 4+4pin plug but this is purely speculation and you shouldn't put to much stock into this theory.
  2. just make sure it the one for power that the issue and you did not use the power one on one of the video cards. there been some issue with that ps on the rog forum with the z77 sablertooth and both plugs not working. you can use a 4 to 8 pin adaptor or contact asus and see if using 4 pins is ok.
  3. the 4x4 works, you just plugged it in wrong. Get a light and study it it is easy to figure out.
  4. Cool, Thanks for the replies, guys! Sounds like I probably plugged in the CPU power correctly, so I guess I'm just gonna have to take everything back apart. I appreciate the feedback!
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