As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU GENERATOR FAILED.FIELD OFF LIGHT ILLUMINATED. LONG HISTORY BIT BPCU FAULTS UNDERVOLTAGE TRIP REPLACE GCU-67. REPLACED GCU NO HELP.REPLACED BPCU AND ECU.ALL NO HELP.REINSTALLED ORIGINAL UNITS. SAME FAULT ALL THE TIME. R & R APU PER AMM. REQUIRES LEAK CHECK. INSTALLED NEW MOUNT NUTS.OPS AND LEAK CHECK GOOD. OK FOR SERVICE. ETOPS CATEGORY 'F': ANY OTHER EVENT DETRIMENTAL TO ETOPS