As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TPA/MDW - FLT 42 - DIVERTED TO ATL WHEN CABIN RATE OF CLIMB WENT TO 1,000 FPM UP, COULD NOT CONTROL RATE IN AUTO OR MANUAL. FOUND LEFT PACK VALVE NOT OPENING. REMOVED AND REPLACED LEFT PACK VALVE, PRESSURIZATION AND OPS CHECK OK PER MM 21-30-0. (X)