What was found
LGA - FLT 2653 - CREW REPORTED THAT DURING CLIMB-OUT FROM BOS, EN ROUTE TO MCO, NUMEROUS COMPONENTS ASSOCIATED WITH THE AC BUS NR 1 FAILED OR BEAME INTERMITTENT. FOUND THE NR 1 GENERATOR FREQUENCY WAS OFF SCALE LOW. CREW STARTED THE APU AND PLACED IT ON THE NR 1 BUS. COMPONENTS RETURNED TO NORMAL. AT FL270, THE APU FAILED. FLIGHT DIVERTED TO LGA AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MX REMOVED AND REPLACED THE NR 1 ENGINE CONSTANT SPEED DRIVE AND OIL COOLER (P/N 6A47-000) PER MM. PERFORMED ENGINE RUN-UP. LEAK CHECK GOOD. ALL ELECTRICAL BUSSES OPERATIONALLY CHECK GOOD. PERFORMED APU RUN. OPS CHECK GOOD. (M)