Corsair cx600 ATX cable 24pin problem

I'm building my computer and after I was finished I turned it on and the fans spun for 1 sec. Then stopped. I didn't know what was the problem so I took out the 24 pin connector and it didn't turn on. When I plug in the 24 pin it doesn't go in all the way. It goes in and stops where there's a little bit to be seen. Aka it won't go in all the way. Can anyone help. How do I get the 24 pin in all the way.


PSU: Corsair CX 600 


Look at the pins in both the connectors on the motherboard and the PSU cable, check to see if any of the pins are bent or broken to see if that's the problem. At the moment that's all i can think of to check. 

Are you plugging it in backwards? There should be a little ~3mm wide tab that tells you the orientation.