As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU GENERATOR QUIT, TRIPS AND FIELD OFF. BPCU BITE SHOWS DP TRIP, GEN POR FDR GEN, OVERLAP ZONE AND UNDER VOLT. PER MM 24-20-00 PD 1 82P ITEM AF ACCOMPLISHED WIRING CHECKS AT GCU AND FOUND T3 WINDING OPEN CIRCIUT, CONFIMED AT GEN THAT GEN AT FAULT. REPLACED GEN ERATOR AND TESTED PER MM. TESTED NORMAL.