Seasonic X660 and the ATX_12V_2x4 connector?
 

I have the Gigabyte Z68X-UD3H and the Seasonic X660. I have never encountered this problem before, but I can't seem to find the ATX_12V_2x4 connector. I looked at every other cable and for the ones that I have found, it just doesn't fit into the back of the PSU. Some of the connectors have a total of 4 pins, but because 2 of them are slightly detached, it won't fit either the motherboard or the back of the PSU.

I looked at the instruction manual and it doesn't say anything about it. My Gigabyte manual said if that isn't installed, the computer won't start. Does anyone here know what's going on? The 24-port connector is indeed installed and the Seasonic manual make it seem like as if that's all that I need to get it working. Does anyone here know what I'll need to do?

See this post....:
Seasonic X660 Gold issue with 12v connector.

split end is for mobo,my old mobo was 4 pin new one is 8 pin hence the split connector ,solid 8 pin goes into psu

Sorry for the late reply, but are you suggesting that I only plug the 4 pin into the motherboard and leave the other 4 pin out? I can't get both in at the same time and I'm afraid of applying too much strength. For some bizzare reason, I can't get the other end of the cable, which is labelled CPU into the PSU.

Flip the cable.

"CPU" text goes into the PSU and the other end goes into the board.

Take a picture of the cable if need be.

Why do I have to flip the cable? I now know that the CPU side goes into the PSU. However, I can't get all 8 pins on the 4+4 end into the 8 pin port on the mobo.

Where are you located?
Dont force it, but take a close look at the plastic edges around the connector on the cable and the motherboard. There may be an edge that is bent inward slightly.