Original post by: Edwin Burnett ,
I have had the same issue also. As a matter of fact this happened to one other MacBook Pro I repaired also. When removing the logic board you may have pulled rather hard on the wire connector that receives power from the logic board. The connectors either slide in place or just snap in place.The early 1150A units had a large white connector that slides in place. The newer models have a black connector that snaps in place. When disconnecting the wires from the board you should gently slide out or lift up the connector. The ones that slide out are white, the ones that snap in place are black. When removing the connector you probably pulled one of the four wires loose from the fan. More than likely, the red one. This can be repaired by re-soldering it back on. Very hard to do. It may be to your advantage to look for a replacement fan. Just be sure to get the right fan and model assembly. The fans of different models are actually the same part number, it is the connector to the logic board that differs. The early 1150A units had a large white connector that slides in place. The newer models have a black connector that snaps in place Because of this the fans are not interchangeable as one may assume they are.