As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING P-06 CHECK EMERGENCY LIGHT SYSTEM TEST THE SYSTEM OK LIGHT DID NOT ILLUMINATE. MAINTENANCE REMOVED AND REPLACED THE LT AND RT OVER WING BATTERY PACKS AT EMERGENCY POWER SUPPLY UNITS 11WL AND 12WL, OPERATIONAL CHECK OF EMERGENCY LIGHT SYSTEM WAS GOOD.