As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT FOR OKO, FLIGHT NR 408, FOUND FLIGHT DECK AIR CONDITIONING SYSTEM EMITS SMOKE WHEN DRIVEN IN WARM, SYSTEM OPERATED GOOD IN COLD MODE. INSPECT AIRCRAFT AND OPERATED SYSTEM IN FULL RANGE TEMPERATURE, NO FAULT FOUND PER MM CH 21.