As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE EMERGENCY BATTERY WOULD NOT DISCONNECT WHEN SELECTED OFF. THE MAINTENANCE VENDOR TROUBLESHOT AND SUSPECTED THE RIGHT GENERATOR MASTER SWITCH P/N MS24524-23 TO BE DEFECTIVE. THE DEFECTIVE MASTER SWITCH WAS REMOVED AND INSTALLED A NEW SWITCH.