What was found
AT FL 350 IN STEADY CRUISE FLT, FELT SLIGHT VIBRATION FOLLOWED BY NR 1 EPR ROLL BACK, NR 1 N1,N2 EGT ROLLBACK. N1 STABILIZED AT 26 PERCENT, EGT 180 DEG NR 1 GEN BREAKER LIGHT ON AND NR 1 LOW OIL PRESSURE LIGHT ON. THRUST LEVEL BOUGHT TO IDLE AND DESCENT STARTED. PASSING FL 300 AND 320 KIAS NR 1 ENG PARAMETERS RETURNED TO NORMAL. ENG OPERATED NORMAL FOR REMAINED OF FLIGHT. RAN QRH FOR NR 1 GEN RESET AND COULD NOT RESET GENERATOR BREAKER. VOLTS AND FREQS NORMAL AND ESSENTIAL POWER OK WHEN NR 1 GEN SELECTED. REMOVED AND REPLACED NR 1 ENGINE FUEL PUMP AND FUEL CONTROL UNIT OPS AND LK CHECKED GOOD PER MM 73-11-01 AND 73-21-01..