As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT T1189/13AUG CREW REPORTED UNABLE TO MAINTAIN CABIN PRESSURE. DESCENDED BELOW 10000 FEET. LANDED ORD WITHOUT INCIDENT. REPLACED RIGHT HAND FLOW CONTROL VALVE AND LEFT AIR CYCLE MACHINE. SYSTEM GROUND CHECKED NORMAL OPERATION.