As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PRESSURIZATION UNCONTROLLABLE AFTER TAKEOFF. MANUAL AND AUTO MODES. RETURNED TO DFW. REMOVED AND REPLACED SKIN AIR OUTLET VALVE (AALA202102229001) AND AVIONICS EQUIPMENT VENTILATION COMPUTER (AALA202102229014) IAW AMM 21-26-00 AND 21-26-34.