Noboot, the issue could be related with the power supply you are using. Have you tried to use a different power supply?
On the following link I was able to see that your Nexus RX-5300 is not a Haswell ready power supply http://www.nxstek.com/Nexus_RX-5300_Modular_Quiet_Power_Supply_530W.htm
You can also try some basic troubleshooting such as testing the system out of the chassis with minimal configuration. (Motherboard, processor, power supply, 1 memory stick)
Remove the CMOS battery and leave the system without it for about an hour. Then put it back on and restart the system. http://www.intel.com/support/motherboards/desktop/sb/CS-028780.htm?wapkw=clear+cmos+battery#datetime
Just in case, remember that low profile memory is not supported by this motherboard.
I would say that you should start replacing the motherboard if you wish. However I recommend you to try the troubleshooting I provided you above.
noboot , did you ever solve your problem? How?
KarimB, please let me know if you are having the same issue? If you do, please provide me detail information in order to help you on this.
KarimB, I noticed that Kevin_Intel is helping you in this thread, https://communities.intel.com/thread/49305. He will continue assisting you in order to find a solution on this issue.
In the meantime, we could wait for NOBOOT, he may give us an update.