As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU FAILED TO START. FAULT LIGHT ILLUMINATED AND EICAS MESSAGE. APU FAULT DISPLAYED. REPLACED APU. AFTER APU REPLACEMENT STILL UNABLE TO START, FOUND BATTERY VOLTAGE DURING CRANK CYCLE AT 8VDC. REPLACED APU BATTERY AND CHARGER PER MM. OPS CKS NORMAL.