As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
APU WILL NOT START IN EITHER ELECTRICAL OR PNEUMATIC START MODE. *S/D* REMOVED AND REPLACED APU BATTERY CHARGER. PROBLEM PERSISTED. FOUND APU STARTER DAMAGED. REPLACED ELECTRIC STARTER (P/N 2704442-4) AND CLUTCH ASSEMBLY. OPERATIONALLY CHECKED NORMAL. SUSPECT CAUSE RELATED TO BOEING SERVICE RELATED PROBLEM (SRP) 777-SRP-49-0028 AND SERVICE BULLETIN 777-24-0024.