As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB TO FL290, UNABLE TO CONTROL CABIN ALTITUDE WITH SINGLE PACK OPERATION. MADE RAPID DESCENT TO FL 9,000, AIRCRAFT DIVERTED TO ATL AND LANDED WITHOUT INCIDENT. PERFORMED PRESSURIZATION CHECK WITH SINGLE PACK AND BOTH PACK OPERATION. BOTH SYSTEMS CHECKED OK. PERFORMED LEAK CHECK, NO TROUBLE FOUND.