As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THAT WHEN THE MAIN SHIP BATTERY WAS PLUGGED IN THE EMER BUS POWERS UP UNCOMMANDED. TROUBLESHOOTING FOUND THE EMER POWER RELAY TO BE DEFECTIVE PN M6106 19-012. THE DEFECTIVE RELAY WAS REMOVED & A NEW UNIT WAS INSTALLED. OPERATIONS CHECKED OK.