As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: CREW REPORTED HIGH CABIN RATE OF CLIMB AND UNABLE TO PRESURIZE. MAINTENANCE FOUND BLOWN DUCT IN FWD AVIONICS COMPARTMENT AFT OF EXTRACTION FAN. REMOVED AND REPLACED DUCT IAW AMM 21-26-42. PRESSURE CHECKED GOOD AT THIS TIME.