What was found
ON RIA FLT 118 - SFO/BOS - 2.25 HOURS INTO FLIGHT, AIRCRAFT DIVERTED TO LAS DUE TO NR 1 AND NR 3 GENERATORS INOPERATIVE IN-FLIGHT. NO FREQUENCY OR VOLTAGE IN EITHER ONE. BOTH GENERATORS HAD PMG ON GROUND AT LAST MAINTENANCE. REMOVED AND REPLACED NR 1 ENGINE GCU - OPS CHECKED NORMAL IAW MM 24-20-00. FOUND NR 3 IDG OVERSERVICED (OIL). SERVICED TO CORRECT LEVEL, RAN ENGINE AND PERFORMED COMPLETE AC GENERATION ADJUSTMENT AND TEST, OPS CKS NORMAL, IAW MM 24-20-00. AIRCRAFT RELEASED TO SERVICE. (X)