What was found
DEN - FLT 305 - EMERGENCY DECLARED (APU PREVIOUSLY DEFERRED) LANDING UNEVENTFUL AT SCHEDULED DESTINATION. LEFT ENGINE DRIVEN GENERATOR DROPPED OFF LINE IN FLIGHT AND WOULD NOT RESET. SWAPPED APU GCU WITH NR 1 ENGINE GCU. RAN NR 1 ENGINE. GENERATOR OPS CHECKS NORMAL PER MM 24-21-00. SAME MALFUNCTION OCCURRED AFTER 2 FLIGHT LEGS DURING TAXI IN TO GATE IN MSP. MAINTENANCE FOUND PIN PUSHED BACK ON FEEDER WIRE OF CANNON PLUG AT NR 1 ENGINE PYLON. REPOSITIONED AND SECURED PIN IN CANNON PLUG. OPS CHECK NORMAL PER MM 24-21-0. (M)