If the EVGA X99 motherboard boots to post code "C" and does not complete POST check your EPS connector.  This is typically caused by poor connection or no connection from PSU to the Motherboards EPS (CPU 8 pin) connection.

Verify that the EPS cable is plugged in, if it is, reseat the cable.  If the PSU is modular, ensure it is plugged into the correct port on the PSU and that the connection is secure.

***Do NOT connect PCI-E 8 pin into an EPS connector, as  the system will NOT function and may damage components***