As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 2234 - EWR - FLIGHT CREW REPORTED BOTH PACK VALVES CLOSED, AND WOULD NOT OPEN. CREW PERFORMED AIR RETURN AND LANDED UNEVENTFULLY. EWR MX REMOVED AND REPLACED NR 1 SLEEVE BETWEEN HEAT EXCHANGER AND DUAL TEMPERATURE CONTROL VALVE (SDR # C2XA10RI160) AND REMOVED AND REPLACED NR 2 BLEED PUSH BUTTON SWITCH (SDR # C2XA10RI161). MX PERFORMED OPERATIONAL CHECK SUCCESFULLY. ACFT WAS APPROVED TO RETURN TO SERVICE.