As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN REDUCING THRUST FOR DESCENT, NR 1 FIRE WARNING ILLUMINATED. RAN EMERGENCY PROCEDURE. TROUBLESHOT FIRE WARNING SYS PER MM 26-10-0. FOUND FAN CASE FIRE LOOP CONNECTOR BKSHL LOOSE AND GNDING. SECURED AND CLEANED ALL CONNECTIONS. AIRCRAFT WAS GROUNDED. FLIGHT 803. (S)