As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO FLIGHT, THE FLIGHT CREW FOUND THAT THE EMERGENCY LIGHTS IN THE FLIGHT DECK AND GALLEY WOULD NOT ILLUMINATE WHEN THE EMERGENCY LIGHTS SWITCH WAS PLACED IN THE ON POSITION. MX REPLACED THE BATTERIES IN BATTERY PACK B5-23 AND THE SYS OPERATED NORMALLY THEREAFTER.