What was found
CABIN EMERG LIGHT: EMER LIGHTS DO NOT TURN ON WITH SWITCH IN ON POSITION. RECHARGE PROCEDURE OF TWO 30 MINUTE PERIODS WITH APU COMPLETED - LIGHTS STILL WON'T COME ON. CORRECTIVE ACTION: TECHS FOUND THE #4 EMERGENCY BATTERY PACK INOP. TECHS REMOVED THE FAULTY UNIT AND INSTALLED AN OPERATOR SUPPLIED NEW BATTERY PACK. OPS CHECK GOOD. NO FURTHER DEFECTS NOTED. WORK PERFOMED PER RADIANTPOWERCORP SIL-CBS28-1-2024-001 REV A