As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ROC - FLT 4902 - CARGO SMOKE WARNING LIGHT CAME ON IN-FLIGHT. FIRED NR 1 CARGO FIRE EXTINGUISHER. RETURNED TO FIELD. INSPECTED CARGO COMPARTMENT WITH NO DISCREPANCIES NOTED. DEFERRED CARGO COMPARTMENT FIRE EXTINGUISHING SYSTEM. REMOVED AND REPLACED (WARNING ELECTRONIC UNIT) WEU. OPERATIONAL CHECK GOOD. CLEARED CARGO COMPARTMENT FIRE EXTINGUISHER MEL. (X)