What was found
WHEN GPU WAS DISCONNECTED AFTER ENGINE START, THE EMER LT NOT ARM CAS ILLUMINATED WITH THE SWITCH IN THE ARM POSITION. ALL EMERGENCY LIGHTS ILLUMINATED IN CABIN. PERFORMED A GROUND RESET & THE CAS CAME BACK ON DURING ENGINE START WITH BATTERY POWER. CONFIRMED ALL EMERGENCY LIGHTS ILLUMINATED IN CABIN WHEN THE EMERGENCY LIGHTS SWITCH IN ARM POSITION. PERFORMED A UNSATISFACTORY OPS CHECK. NOTIFIED MCC. CUSTOMER ELECTED TO REPLACE BOTH EMERGENCY LIGHTING BATTERIES. REMOVED AND REPLACED BATTERIES 182. PERFORMED A SATISFACTORY OPS CHECK OF THE EMERGENCY RIGHTING SYSTEM WITH NO FAULTS OR DEFECTS NOTED. WORK PERFORMED IAW MM 33-52-01.