What was found
SEA - INTERMITTENT MASTER CAUTION FOR FIRE DETECTION. FAULT "A" FOR THE NUMBER 2 ENGINE. CYCLED OFF AND ON ABOUT 4 TIMES OVER 3 MINUTES IN CRUISE, THEN NO FURTHER INDICATIONS FOR THE REST OF THE FLIGHT. MAINTENANCE INSPECTED THE FIRE LOOP FOR DAMAGE, NONE NOTED. CLEANED AND INSPECTED THE CONNECTOR FOR THE FIRE LOOP AND THE CONTROL AMPLIFIER. PERFORMED OPERATION CHECK WITH NO DEFECTS NOTED. RAN ENGINE AT 93 PERCENT FOR 15 MINUTES WITH NO DEFECTS. DISCREPANCY NOT DUPLICATED. AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.