As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LGA-MHT FLIGHT#3534. CREW REPORTED DURING TAKEOFF, BAGGAGE COMPARTMENT SMOKE WARNING LIGHT ILLUMINATED. AIRCRAFT RETURNED TO FIELD WITHOUT INCIDENT. MAINTENANCE REPLACED THE MASTER WARNING CONTROL BOX AND PERFORMED TEST OF SMOKE DETECTOR. NO FURTHER DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.