What was found
THE SMOKE WARNING CAME ON INTERMITTENTLY, ABOUT 6 TIMES, EACH TIME EXTINGUISHING AFTER ABOUT 3 SECONDS. MAINTENANCE INSPECTED THE CARGO AREA AND FOUND NO EVIDENCE OF SMOKE OR OVERHEAT. TESTS WERE PERFORMED ON THE 1 AND 2 SMOKE DETECTORS. BOTH CHECKED GOOD. THE NR 2 SMOKE DETECTOR WAS DEFERRED AS A PRECAUTION. THE AIRCRAFT WAS RETURNED TO SERVICE. SDR TO REMAIN OPEN PENDING FURTHER INFORMATION. THE SMOKE DETECTORS WERE REPLACED, OPERATIONAL CHECKS WERE GOOD, AND THE AIRCRAFT WAS RETURNED TO SERVICE.