What was found
(CAN) ACFT WAS IN-FLIGHT FOR ALMOST 3 HRS, WHEN THEY HAD A LT GENERATOR FAILURE. APU WAS STARTED BUT THEN FAILED. APU STARTED UP AGAIN BUT HAD REDUCED ELECTRICAL OUTPUT. A DIVERSION WAS THEN SET UP. WHILE ENROUTE TO THE CREW THEN HAD A COMPLETE APU AUTO SHUTDOWN, AND THEN DIVERTED TO NEAREST SUITABLE ALTERNATE. CREW DID DECLARE A PAN PAN MESSAGE WITH ATC, AND AN OVERWEIGHT LANDING WAS CONDUCTED. REPLACED LT-ENGINE IDG OPS CHECK OK IAW AMM 24-11-01-004-001-0-02 WITH ENGINE IDLE RUN. REMOVED PN 766088B, SN Y0359.