I just got the motherboard in the mail today, and put it in a PC with an already functioning PSU & GPU, using a CPU that worked previously in another motherboard. The board would power up with all status LEDs fine and operational, but the GPU fans would run at full speed (tried two different GPUs), and you have to hold down the power button to turn off the motherboard. On one of the seven segment displays there was a C, and the other one was blank. I looked up this error code, and it's apparently pre-POST failure, so I did the suggested troubleshooting procedures of switching the BIOS, re-seating the CPU, and checking the pins (none are bent, I have a picture but links aren't allowed and uploading doesn't seem to work).
 
What should I do? I also have a $50 Mail-in-rebate that I haven't sent in yet, which needs to be sent within 30 days of purchase.
 
Thanks!
 
[P/N: 130-SB-E675-KR] 
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(dot) dropbox (dot) com/s/7tiifc85ifbkp6n/IMG_6545.jpg]

This can be a few things.  To confirm, what CPU are you running on the board?  Are you connecting a solid 8pin connection to the 8pin CPU power?  Is it a 4+4pin or a 6+2?  If it is a 6+2 it is wired differently and is only for video cards. 

The CPU is certified for the board. We have seen sometimes where a power supply will work on one motherboard not another.  Try with the other power supply as well as try the other BIOS that is on the board.  You can do so by moving the jumper at the bottom right over pone pin then turning on the system.

Sorry, missed that.  Just about every time someone says switched BIOS or tried another they mean flashed another one so it just did not click there for me.
 
Post back the results of the other power supply. You can also e-mail me directly at mattm@evga.com.