As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
5 MINUTES AFTER TAKEOFF RECEIVED CARGO SMOKE MESSAGE. PERFORMED EMERGENCY PROCEDURE AND RETURNED TO AIRPORT. INDICATION WAS NOT STEADY MESSAGE WOULD GO ON AND OFF. INSPECTED CARGO BAY AREA, NO SIGN OF SMOKE OR FIRE. REMOVED AND REPLACED SMOKE DETECTORS IAW MM 26-15-0, OPS CHECKS GOOD.