What was found
CARGO SMOKE ALARM ACTIVATED IN FLIGHT, THE NR 1 CARGO FIRE EXTINGUISHER WAS ACTUATED, THE LIGHT STAYED ON. THE AIRCRAFT RETURNED TO BTR WITHOUT INCIDENT. UPON INVESTIGATION, MAINTENANCE FOUND THE FORWARD CARGO SMOKE DETECTOR TO BE INOPERATIVE. REPLACED FORWARD SMOKE DETECTOR AND THE NR 1 CARGO FIRE BOTTLE, NO FURTHER PROBLEMS.