As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ZONE E CABIN TEMP UNCONTROLLABLE, WITH TRIM AIR ON TEMP IS 55-60 F WHILE FWD CABIN IS TOO HOT LOCKED . REMOVED AND REPLACED LEFT CTC P# 810200-3 S# 98064644 OFF P# TEMP CONTROLER OPS NORMAL AT THIS TIME. NOTE CTC WAS CHANGED DUE 810200-3 S# C96080208 ON IAW AMM 21-61-01. INSTALLED CTC OPC P# TO POSSIBLY BAD FROM STOCK CAUSING NEW TEMP FAULTS PARTS 2173BCG015-13 ONTO CHANNELS A AND B.