As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIVERSION TO YJT DUE TO "MAIN DECK CARGO SMOKE DET ZONE 4 LIGHT ILLUMINATED WITH CARGO AND MASTER FIRE ANNUNCIATOR LIGHTS ILLUMINATED. AFTER LANDING RETESTED OKAY (NORMAL). AIRCRAFT ALSO SUSTAINED AN OVERWEIGHT LANDING. SWAPPED ZONE 3 AND 4 SMOKE DETECTORS A/B PER AMM 26-14-00. ZONE 4 SYSTEM A P/N ON 2156-646 S/N 393 SYSTEM B P/N ON 2156-10C S/N 869. SYSTEMS CHECKED NORMAL. PERFORMED OVERWEIGHT LANDING PHASE 1 INSPECTION IAW AMM 5-51-39. NO DAMAGE NOTED.