As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MAIN CARGO FIRE INDICATION DURING PRE-FLIGHT. PERFORMED A FIRE LOOP TEST IAW AMM 26-11-01, NO FAULTS NOTED, OK FOR SERVICE. REMOVED AND REPLACED THE MAIN CARGO BAY CIRCUIT CARD M20206 IAW AMM 26-10-01. SYSTEM OPS CHECKED GOOD AT THIS TIME.