As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JFK - CREW REPORTED UNABLE TO PRESSURIZE AIRCRAFT ON CLIMBOUT. EMERGENCY DECLARED FLIGHT RETURNED JFK LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED LEFT AND RIGHT OUTFLOW VALVE ASSEMBLIES. SYSTEM GROUND CHECK NORMAL OPERATION.