As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTS ALL 4 CARGO FIRE SUPPRESSION LOOP FAIL LIGHTS ARE ON. *S/D* IN THE AFT CARGO COMP, FOUND THE A LOOP NR 1 AND B LOOP NR 2 & 3 DETECTORS INOP. SWAPPED NR 1 DETECTORS. NOW AFT CARGO A LOOP IS OPERATIONAL, AFT CARGO B LOOP IS INOP. REPLACED 'A' AND 'B' LOOP DETECTORS, CHECKS NORMAL.