X99M KILLER 3.1 DEBUG CODE 67

Code 67 is a "chipset initialization error" according to your user manual. Now the manual recommends clearing CMOS but that is not the only possible cause. Before we get into any additional troubleshooting did you try using this method to clear CMOS? This way is more or less foolproof and should reset everything including the RTC (real time clock). If that still does not resolve the issue then check to make sure your CPU is properly seated and there are no bent pins on the motherboard also reseat your RAM and GPU. If none of this helps then you can try a minimal boot scenario, 1 stick of RAM, onboard iGPU, CPU and no other devices connected.