If you've really gone through the entire checklist with no success then I guess it's time to try sending in parts for RMA. I would guess that either the 4-pin CPU power cable isn't connected or the problem lies with your RAM. Which exact RAM kit do you have? All of these kits fit your description:
The Kingston HyperX RAM needs insane voltage to get its rated speed and timings. Did you follow the steps to try one stick of RAM and to try each stick by itself in each RAM slot? You will need to manually set the RAM speed/timings/voltage to the manufacturers specs in the BIOS for that RAM to work correctly.
Are both 6-pin power connectors plugged into your GPU? Do you have a system speaker installed so you can listen for beep codes?
Sounds like you didn't put the RAM in the correct slots specified in the motherboard. There is a certain way to insert tri chan or dual chan ram. If you don't comply with the instruction your PC wont' POST.