What was found
AIRCRAFT GROUNDED - WELS (WIRELESS EMERGENCY LIGHT SYSTEM) BATTERY DATE CHECK REQUIRED (SEE ORIGINAL MIC 70568849). TROUBLESHOOTING WBU (WELS BATTERY UNIT) 30. WBU 30 WAS PREVIOUSLY REPLACED BUT DID NOT SEAT CORRECTLY, THEREFORE DID NOT REPORT AS REQUIRED. SECURED LOOSE BATTERY, OPERATIONAL CHECK OKAY, AND PERFORMED SYSTEM CONFIGURATION REPORT (SCR) PER AMM 33-51-00-09A-300D-A, AS REQUIRED.