Attaching RAM to motherboard

[scott1939392]

I'm currently using MSI x99s Gaming 9 Ack, and have RAM 4 sticks of 8 gb Corsair Vengeance. Somehow I'm not able to attach more than 2 sticks, otherwise my motherboard won't boot up. I've tried many different combinations on the motherboard, and consulted many people, who have said things like put the RAM in the slots that are 2 4 6 8, and following the manual as well. My computer still can run with 2 sticks, but I'm not getting what I paid for.

 

[alexoiu]

Are there specific RAM slots not working? If yes, try removing the CPU, taking a clear picture of the CPU socket, uploading it on imgur and posting the link here.