As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING MAINTENANCE INSPECTION FOUND THE EMERGENCY LIGHTS ON EPSU NR 4 INOPERABLE. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED NR 4 EPSU IAW W/C 33-00. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.