What was found
ORD - FLT 4023 - WHEN FLIGHT ATTENDANT TESTED THE EMERGENCY LIGHTS, THEY INITIALLY CAME ON, THEN IMMEDIATELY WENT DIM, AND THEN, FAILED TO ILLUMINATE AT ALL AFTER 10 SECONDS. REMOVED AND REPLACED EMERGENCY LIGHT BATTERY PACKS 1 THROUGH 4 IAW EMB-145 AMM 33-90-04. OPERATIONAL CHECK GOOD. REF: OPER CNTRL NR SIMA990779, AND, 99ZZZX1654 AND 99ZZZX1655.