What was found
ON TAXI OUT, GOT MID 1 MAIN DECK LOOP FAULT. COMPLIED WITH MEL, SELECTED AFFECTED LOOP OFF AND CONTINUED DURING CLIMB GOT MAIN DECK CARGO SMOKE WARNING PASSING FL 200. COMPLIED WITH RED ECAMS AND DURING AMBER ECAMS WARNING CEASED. CONTINUED WITH EMERGENCY RETURN AND LANDING. AFTER LANDING EMERGENCY EQUIPMENT FOUND NO EVIDENCE OF SMOKE OR HOT SPOTS. REPLACED SMOKE DETECTORS AT POSITIONS 4WU AND 22WU PER A300-600 AMM SUPP 26-19-12. POSITIONS 3WU AND 8WU REPLACED ON PREVIOUS ENTRY. ALL SMOKE DETECTORS WERE INSTALLED PER EA NR 6-2612-1 03614.