As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS SIGNIFICANT SYSTEM - APU SHUTDOWN AT GATE. PERFORMED APU BITE. NO FAULTS NOTED. RESTARTED APU - COULD NOT GET GENERATOR ONLINE. REPLACED APU GCU PER AMM 24-22-02. NO HELP. RE-INSTALLED ORGINAL APU GCU PER AMM 24-22-02. REPLACED APU GENERATOR PER AMM 24-21-01. OPS AND LEAK CHECK GOOD.