As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BPCU FAULT APU GCU. REPLACED APU GCU, NO HELP. REPLACED APU GCU, NO HELP. WHEN LT GEN SELECTED APU GEN OFF LT ILLUM AND WOULD NOT COME BACK ON LINE. FREQS AND VOLTS GOOD. CYCLED CB FOR APU GEN CONT, NO HELP. REPLACED NR 1 ENG IDG AND BPCU. ALL AUTOMATIC SWITCHING OF GENERATORS, OPS CHECK NORMAL.