ello this could come in handy for ya to get ya fan working without it having to be hooked up to the computer what im about to tell ya works brilliant for me i have 3 fans hooked up together on a dc adapter

on the fans there is 3 wires red,black,yellow the red and black wires are ya elctical wires and the yellow is a fan speed controller wire that monitors rpm
right snip off the yellow wire as it is not needed and take the red and black wires peel off the insulation slightly and wire them to a 12volt dc adapter you can buy these from any hardware stall
snip off the end of ya adapter and there are 2 wires you will notice they are both black but one of them will be marked with lil white lines this is the wire ya will be attaching the red wire too twist them together insulate with electrical tape and do the same on the other black wire
then you are good to go
plug it in dude and thats it
cheers hope this helps