The rear fan is plugged into port 6. If I swap it, some of the other fans will not light up, but it will(so I know its not a faulty fan). Right now the fans are configured where the front 3 are plugged into 1-2-3(default with the case). The one closest to front on top is plugged in 4, then the next one on top is 5, and the rear is 6.