As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PRE-FLIGHT, CREW NOTICED THE MID CABIN EXIT SIGN WAS INOPERATIVE. GROUND MX CREW CHARGED THE BATTERIES WITH GROUND POWER, RESET THE SYSTEM, AND PERFORMED AN OPS CHECKED WITH SATISFACTORY RESULTS. THE AIRCRAFT WAS RETURNED TO SERVICE.