As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND ACFT GROUND POWER DISCONNECTED. MAIN DC AND AUX DC BATTERIES DRAINED. TR UNIT ANNUNCIATOR ILLUM. ON OVERHEAD PANEL TR3 SHOWS 0 VOLTS. BAT BUS SEC 1 CIRCUIT BREAKER POPPED. 28V DC TR3 DC IND CIRCUIT BREAKER POPPED. GROUNDED YES. R&R AND TESTED MAIN AND AUX BATTERIES. RESET ALL POPPED CIRCUIT BREAKERS IAW AMM AND ALL SYSTEMS CHECK OK. OPS NORMAL. ETOPS M/C LYONS CONSULTED. ROTABLE PARTS VERIFIED WITH SEAMC MARK.