As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONTROL CABIN ZONE TEMP LIGHT ILLUMINATES ON MASTER RECALL. GROUNDED - YES. PERFORMED PACK TEMP CONTROL BITE ON PZTC #1 AND PZTC #2 REF B737-800 FIM 21-62 TASK 801. FOUND FAULT FOR FLT DECK TRIM VALVE ON PZTC #2. REMOVED AND REPLACED FLT DECK TRIM AIR VALVE REF B737-800 AMM 21-61-21/401. OPS AND LEAK TEST GOOD. ETOPS GROUND VERIFICATION SUCCESSFUL.