As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 221 - DURING CLIMB THROUGH 7,500 FEET, THE CARGO 'SMOKE' LIGHT ILLUMINATED. THIRTY SECONDS LATER, IT EXTINGUISHED. FEW MINUTES LATER, THE 'SMOKE' LIGHT CAME BACK ON FOR 30 SECONDS. THE AIRCRAFT RETURNED TO BDL AND NO OTHER PROBLEM. (NO EMERGENCY WAS DECLARED). MAINTENANCE FOUND THE NR 2 CARGO SMOKE DETECTOR DIRTY AND CLEANED AS REQUIRED. FUNCTION CHECKED, NO DEFECTS NOTED. (X)