As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 4-DAY CHECK, OPERATIONAL TEST OF THE EMERGENCY LIGHT SYSTEM FOUND THE LT OVERWING EMERGENCY POWER SUPPLY UNIT FAULTED. MAINTENANCE REMOVED AND REPLACED THE LT OVERWING EMERGENCY POWER SUPPLY UNIT (11WL), OPERATIONAL CHECK WAS GOOD.