Arial problem

I've had a Mac Pro for about four years for music, i've just tried to connect to the internet and there's no signal.
I checked inside to find that the connectors had not been connected to the Airport card, I connected them as per instructions, 2 to the top 3 to the bottom BT off and 4 off, but I still can't get a signal.
I've tried my Mac Book and I get a signal so there's something wrong with My Mac Pro, does anyone know where the other end of the arial wire goes so that I can check if that's connected? any suggestions please.