What was found
(CAN) DURING CRUISE AT 16,000 FT, AC DEPRESSURIZED W/ILLUMINATION OF MSTR WARN LIGHT, MSTR CAUTION LIGHT, GPWS WARN LIGHT. SYS THAT REPORTED TO STOP WORKING: FMS, NAV, TRANSPONDER SYS. NR2 ADF WAS REPORTED TO BE WORKING, WAS USED TO LAND. ON APPROACH, LG WAS SELECTED DOWN, FLAPS EXTENDED, CAUTION LIGHT WAS REPORTED TO EXTINGUISH: AUX INV, RUD FULL, NR2 RYD HYD. WHEN AC WAS ON GROUND, BUS TIE SWITCH WAS SELECTED, AC STARTED TO PRESSURIZE. LT STARTER/GEN FAILED TO GENERATE PWR AND TO START ENGINE. NEXT START, NR1 GCU AND STARTER/GEN REPLACED, GROUND CHECKED IAW 24-31-03, 24-31-01 NO DEFECTS EVIDENT. START/GEN WAS CONFIRMED THAT UNIT HAD FAILED DUE TO NO GENERATION, SHUNT FIELD OF STATOR WAS OPEN CIRCUIT.