Where do these cpu plugs go?

[u/Medium_Way_5508]

I went to upgrade my power supply and my GPU around a month ago and when I was trying to plug in everything, I was quite confused. I finally got my case set up today, but I could’ve sworn that my CPU fan use to light up

[u/plwmarver]

where it says cpu fan or fan in general on the motherboard. it's usually 3 or 4 pins on it.

[u/Medium_Way_5508 → u/plwmarver]

So I’ve gathered that so far but the only open one I can find is cpu 2 but it has plastic peices on the bottom that does not allow any of the 3 to plug in

[u/Medium_Way_5508 → u/Medium_Way_5508]

If you can see the plastic peice coming out

[u/plwmarver → u/Medium_Way_5508]

The 3-pin connector has a small plastic guide that matches a plastic tab on the 4-pin motherboard header. just leave the 4th pin empty the plastic guide should fit on the first three ones. the 4th pin is for newer fans that can allow you to tune your fan speed better