New Fans Don't Work

So i am building a new box with 2 fans. My old one only has 1. I bought the new fan at best buy just like my old one, it's the same brand, everything.
But for some reason it doesn't work. Did they change something. I tried powering my old fan with one of my new adapters and it worked fine so I know it's not the adapter, it has to be the fan. What is the problem? This is the last step in my new box

if it's new then take it back to best buy for an exchange, or money back

already cut the connector off the end to hook it up to my adapter

rewire it and try it again