As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ATTENDANT RESET THE SWITCH FOR THE READING LIGHTS IN THE MAIN CABIN (USING THE PSU) AND THE EMERGENCY LIGHTS CAME ON. TURNED OFF THE EMERGENCY LIGHTS WITH THE SWITCH IN THE FLIGHT DECK. TRIED ARMING THE EMERGENCY LIGHTS AGAIN, BUT THEY CAME ON IN THE "ARMED " POSITION. TURNED THEM OFF AGAIN. REPLACED THE FORWARD LEFT EMERGENCY POWER SUPPLY UNIT BATTERY AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK IAW AMM 33-51-38 & 33-51-00.