As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT, SMOKE WAS NOTICED ON UPPER DECK. CREW REST SMOKE DETECTOR ACTIVATED AND UPPER DECK AIR SUPPLY BUTTON ILLUMINATED. COCKPIT AND LOWER DECK WERE CLEAR OF SMOKE. AFTER A FEW MINUTES, SMOKE/ODORS DISAPPEARED AND AIR SUPPLY RESET. NO FURTHER PROBLEMS. INSPECTED EVIDENCE OF OIL LEAK IN APU. NO TROUBLE FOUND. NO EVIDENCE FOUND WITH ALL 3 PACKS RUN, AND NO EVIDENCE SMELL OF SMOKE PER AMM 49-12-00.