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