Dell Laptop Fan not running?

I have a 1994 Dell Inspirion 600M. The fan is not running at all. I took the laptop apart and cleaned the fan. Too the plug that is attached to the board came off when I tried to unplug the fan. (I reattached this to the board) I tested the fan seperatly by plugging into a enquirer, it ran forfeit. I put everything back equally and the device will still not run. Any ideas?