As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE SITTING ON THE RAMP & LOADING IN KSCK MAIN CARGO LOOP 1, FIRE ALARM & BELL CAME ON. THEN EXTINGUISHED AFTER A FEW SECONDS, MTX VERIFIED NO FIRE IN MAIN CARGO. PERFORMED OPS TEST I.A.W AMM 26-14-00. OPS CHECK GOOD A/C RELEASED ETOPS 180 AND RETURNED A/C TO SERVICE.