As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ETOPS - INFO TO MX. COCKPIT ZONE CONTROLLER IS MALFUNCTIONING. PER MOC. ZONE CONT RESET IN FLIGHT NO CHANGE. COCKPIT TEMP IS TOO HOT. THEN TOO COLD. AND AIR COCKPIT KNOB IS INEFECTIVE. REPLACED ZONE CONTROLLER AND CKPT TRIM AIR VALVE (637HK) PER AMM 21-63-34 AND AMM 21-63-51. OPS AND LEAK TEST OK. OK FOR SVC.