As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING PRE-FLIGHT INSP, AIRCREW NOTICED THE OVERHEAD EMERGENCY EXIT SIGN AT ROW NR4 NOT ILLUMINATING. MX CREW FOUND THE PS5 EMERGENCY BATTERY PACK TO BE INOPERATIVE. THEY R & R THE EMERGENCY BATTERY PACK PS5, PERFORMED EMERGENCY LIGHT OPS CHECK AND SYS PERFORMED SATISFACTORY. ACFT WAS RETURNED TO FLIGHT STATUS.