As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAXI OUT CABIN PAC RAN AWAY HOT (SUPPLY 220+) AND WAS UNCONTROLLABLE IN AUTO OR MANUAL. THE CABIN APPEARED HAZY AS THOUGH THEIR MIGHT BE SMOKE BUT LACKED ODOR. FOUND CABIN ACM SEIZED. R & R CABIN ACM IAW AMM 21-51-00. OPS NORMAL.