As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW CONFIRMED THAT THE EMERGENCY LIGHT SYSTEM DID NOT ILLUMINATE ANY LIGHTS WHEN TESTED AND WAS INOPERATIVE WITH THE SWITCH IN ARM AND ONLY GROUND POWER AS A SOURCE DURING INITIAL POWER-UP. MAINTENANCE REPLACED ALL EMERGENCY LIGHT BATTERY PACKS AND THE SYSTEM RETURNED TO AN OPERATIONAL CONDITION.