What was found
AIR TURNBACK ON ROTATION, NR 4 GENERATOR WARNING. DID A GO-AROUND AND LANDED WITHOUT INCIDENT. ACCOMPLISHED OVERWEIGHT LANDING INSPECTION, NO DEFECTS NOTED. FOUND NR 4 GCU CENTER CANNON PLUG LOOSE. RECONNECTED, RAN ALL ENGINES AND CHECKED ELECTRICAL SYSTEM, OPS FOUND ALL NORMAL PER MM 24-10-0.