As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO MAINTAIN CABIN PRESSURIZATION IN SIGNAL SOURCE. REPLACED SEVERAL VALVES PARTIALLY CORRECTED PROBLEM FURTHER INSPECTION REVEALED BLEED AIR T-FITTINGS ON RIGHT HAND PRECOOLER INBOARD AND OUTBOARD SIDES CRACKED. REPLACED BOTH T-FITTINGS, PERFORMED OPERATIONAL CHECK FLIGHT AND FOUND SATISFACTORY.