As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, CREW REPORTED A CARGO COMPARTMENT FIRE WARNING. BOTH FIRE BOTTLES WERE DISCHARGED AND AIRCRAFT RETURNED TO IAH WITHOUT INCIDENT. REMOVED AND REPLACED DEFECTIVE CARGO COMPARTMENT SMOKE DETECTOR AND FIRE BOTTLES. OPERATIONALLY CHECK OK.