What was found
EXTERNAL POWER DROPPED OFF LINE. APU STARTED AND PLACED ON BUSSES. ABOUT 5 MINUTES LATER APU GENERATOR DROPPED OFF LINE. NO APU AVAILABLE LIGHT. EXTERNAL POWER RESET AND PLACED BACK ON BUSS. APU AVAILABLE LIGHT CAME BACK ON AFTER A FEW MINUTES. ACFT GROUNDED. PERFORMED APU BITE IAW FIM 49-60, TASK 801. NO FAULTS, CURRENT OR RELEVANT FAULT HISTORY, FOUND. RAN APU & APPLIED GEN BUSSES & ELECTRICAL LOAD FOR 15 MINS IAW AMM 49-11-00, NO FAULTS FOUND. VOLTS & FREQUENCIES NORMAL AND APU GENERATOR REMAINS ON LINE. NO HISTORY LAST 30 DAYS. ETOPS SIGNIFICENT SYS - GROUND VERIFICATION SUCCESSFUL.