As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA - LEFT MAIN BUS FAILED WHILE ON GROUND. RESET BUS FAULT PER EMERGENCY CHECKLIST, EVERTHING NORMAL. MAINTENANCE PERFORMED OPERATIONAL TEST OF THE MAIN 28V DC GENERATION SYSTEM. NO DEFECTS NOTED. PERFORMED OPERATIONAL TEST AND DATA RETRIVAL FROM EPCU. NO DEFECTS OR FAULTS NOTED. OPERATIONAL CHECK GOOD. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.