As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ATB - APU FAULT,APU AUTO SHUTDOWN, FAILED TO RESTART ABOUT 1 HR OUT MOC RECMD TURN BACK. FOUND FAULT LOP SW/OIL PUMP/DEOIL FUEL SUPPLY/FCU/FLOW DIVIDER- FOUND METAL SHAVINGS ON GEARBOX SIDE LAST CHANCE FILTER/ SCAVENGE PUMP FILTER. METAL DEBRIS IN GEARBOX OIL. REMOVED AND REPLACED APU PER TASK CARD 330-49-HWI-09 WO 285556