What was found
EMERGENCY LIGHTING CONSISTING OF AFT OVER WING LIGHT, EXIT SIGN ON BULKHEAD SEAT NINE, EXIT SIGN OVERLAP, SEAT LAV OVERHEAD LIGHT ALL INOPERABLE WITH THE EMERGENCY SWITCH IN ARM AND MAIN BATTERIES OFF. ALSO WITH SWITCH IN ON POSITION AND MAIN BATTERIES OFF NO EMERGENCY LIGHTS COME ON. CORRECTIVE ACTION: REPLACED NR 1, 2, 3, 4 EMERGENCY BATTERY CHARGING SYSTEMS. REMOVED AND INSTALLED P/N"S CBS28-1. REMOVED S/N NR 1 006771, NR 2 2755M, NR 3 2052M, NR 4 1702M DUE TO INTERNAL FAILURE AND INSTALLED REPAIRED EMERGENCY BATTERY CHARGER SYSTEM P/N CBS28-1 S/N NR 1 0062891, NR 2 005817, NR 3 005624, NR 4 005873.