As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON CLIMB THROUGH FL290 CARGO SMOKE 6TH POSITION LIGHT ILLUMINATED AND FIRE WARNING BELL SOUNDED. ACFT RETURNED. ON ARRIVAL, NO SMOKE DETECTION LIGHTS WERE ILLUMINATED ON FE PANEL. CARGO AREA INSPECTED FOR SMOKE. NONE FOUND. SUSPECTED FAILURE OF NR 6 SMOKE DETECTOR. PART REMOVED AND REPLACED. SYSTEM FUNCTION CHECKED SERVICEABLE.