As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LGA WOULD NOT PRESSURIZE AFTER TAKEOFF AND RETURNED TO DEPARTURE. PRIOR TO DEPARTURE THE ACFT DISPLAYED AN AEVC FAULT ON ECAM. DETERMINED THE FAULT WAS CAUSED BY A FAULTY ISOLATION VALVE 24HQ. AFTER LANDING, DISCOVERED SEVERAL EQUIPMENT COOLING DUCTS HAD COLLAPSED OR WERE OTHERWISE DAMAGED. THE DAMAGED DUCTS, AEVC COMPUTER 10 HG AND THE FOLLOWING VALVES 24HQ AND 22HQ WERE REPLACED. NO PREVIOUS OR RECENT HISTORY ON THE EQUIPMENT COOLING SYSTEM OR FURTHER FAULTS ON SUBSEQUENT FLIGHT.