As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LAS - EEL - DURING 4-DAY CHECK FUNCTIONAL TEST OF EMERGENCY LIGHT SYSTEM, THE FORWARD LT EMERGENCY POWER SUPPLY UNIT HAD AN INTERNAL FAULT. MAINTENANCE REMOVED AND REPLACED LT EMERGENCY POWER SUPPLY UNIT (10WL), OPERATIONAL CHECK WAS GOOD.