As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUX MID ZONE TEMP CONTROLLER FAULTING AUX MID TRIM VALVE. REPLACED AUX MIDTRIM VALVE, NO HELP, STILL FAULTS AUX TRIM VALVE ON CONTROLLER & UNABLE TO MOVE VALVE POSITION FROM FLIGHT DECK. SUSPECT BAD VALVE FROM STOCK PCN (643-9023). REPLACED AFT AUX TRIM VALVE IAW MM21-61-07.