|Look closely at both edges of the cable. One edge will have a red stripe running the length of the cable. That side connects to the # 1 pin side of the connectors. Also, the cable may have one of the holes filled in to match a missing pin on the motherboard and drive connections. That will be toward the # 1 pin side also. But if yours is that way then it'll only connect one-way anyway.|
As mentioned above, the cable is likely connected OK but since you didn't give any history of what happened to it I thought it best to list all the possibilities.