As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW SMELLED SMOKE/ODOR IN THE CABIN DURING FLIGHT. FOUND SLIGHT DISCOLORATION OF DUCT DUE TO AN OVERTEMP. NO DELAMINATION NOTED AND NO OTHER SIGN OF WIRING OR COMPONENT DAMAGE. WHILE TROUBLESHOOTING FOUND RELAY INSIDE OF VIP CABIN TEMP SWITCH PANEL THAT WAS DEFECTIVE, NOT ALLOWING COCKPIT CONTROL OF CABIN TEMP IN THE AUTO POSITION. PILOTS HAD TO SWITCH TO MANUAL MODE TO OVERRIDE VIP TEMP SWITCH PANEL. (K)