What was found
DURING FLIGHT 2772, BGM/DTW THE LT AC GENERATOR FAILED ON ARRIVAL INTO DTW. AC GEN STARTED TO SMOKE AND SPARK ON APPROACH. DECLARED AN EMERGENCY, SHUTDOWN ENGINE ON THE GROUND IN DTW. MX REPLACED LT AC GEN P/N 31342-043, S/N ON 96023. REPLACED THE AC GCU P/N 51634-002, S/N ON 96026. FOUND LT PGB DAMAGED DURING LT AC GEN CHANGE, MX REPLACED LT ENGINE P/N CT7-9B S/N ON GE-E785121, REPLACED LT PGB P/N 5074T51610, S/N ON IHI00461. DURING ENGINE CHANGE NOTED BACKSHELL OF CONNECTOR 1XAP1 FOR LT AC GEN DAMAGED, MX PERFORMED TEMPORARY REPAIR OF CONNECTOR AND ASSOCIATED GROUNDING HARNESS.