What was found
AIRCRAFT WAS NOT GROUNDED: DURING PERIODIC SERVICE CHECK MAINTENANCE FOUND FAULT MESSAGE FOR EMERGENCY POWER SUPPLY UNIT 15WL BATTERY DURING EMERGENCY LIGHT TEST. MAINTENANCE REPLACED EMERGENCY POWER SUPPLY UNIT 15WL (AALA202309058119) AND BATTERY (AALA202309053141) PER AMM 33-51-38. MAINTENANCE ALSO REPLACED THE CEILING EMERGENCY EXIT SIGN BETWEEN THE L2 AND R2 DOORS PER AMM 33-51-17. (AALA202309052187) A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.