As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND FAILED TO PRESSURIZE ON CLIMB-OUT, RETURNED TO ORD. PERFORMED FIM TASK 21-30-00-810-A01, AMM TASKS 45-45-00-970-801-A01 AND 21-31-00-910-801-A01 WITH NO DEFECTS. AIRCRAFT PRESSURIZED AND DEPRESSURIZED NORMALLY. AIRCRAFT RETURNED TO SERVICE.