As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DEN - FLT 233 - UPON ARRIVAL, FLIGHT CREW REPORTED THE LEFT PACK TEMPERATURE CONTROL WENT TO FULL HOT IN AUTOMATIC MODE CAUSING SMOKE IN THE CABIN. SMOKE DISSIPATED WHEN CONTROL WAS REPOSITIONED TO MANUAL. REPLACED THE LEFT PACK VALVE, AND SYSTEM CHECKED OKAY.