If what oofun says didn't work, open your computer when its completely disconnected, and rub your hands with a metallic surface. Having done that, check if all cables are properly plugged into the fan. If you have a fluke tester, check electricity is passing through this cables. To do so, just put the black end on the black wire and the red end on the red wire, but with the computer off. When they are sitting still, but making contact with the wires, turn it on, and observe the fluke tester. If the current is direct 5v, it means thereīs electricity through it, therefore, it should work...Else, itīs just broken, buy a new one.