What was found
AIR RETURN, UNABLE TO PRESSURIZE CABIN. TROUBLE SHOOTING IN PROGRESS. REPLACED EQUIPMENT COOLING SYSTEM CONTROLLER. SYSTEM CHECKS NORMAL.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AIR RETURN, UNABLE TO PRESSURIZE CABIN. TROUBLE SHOOTING IN PROGRESS. REPLACED EQUIPMENT COOLING SYSTEM CONTROLLER. SYSTEM CHECKS NORMAL.