You need to buy a new motherboard. Or give it back to your friend for a refund if you bought it broken and didn't know it.
There's no fixing a broken pin for the ordinary consumer.
What I really wanna know is, would it still run because, there are light green pins surrounding the (18,AW) pin. From what I've watched then, theoretically it should work, but I'm not so sure about the 16,AW pin.