As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN PRESSURIZATION IN AUTO, CABIN PRESSURE CANNOT BE MAINTAINED (CABIN ALTITUDE RISES) IN DECENT. OK IF ENGINE POWER ADDED. PRESSURIZATION SYSTEM INADEQUATE WITH POWER BACK SAME FOR BOTH STANDBY AND AUTO. SUPPLEMENTAL DATA UPDATE FOUND LOW ENG BLEED PRESSURE AT IDLE. BOTH NR 1 & NR 3 HI PRESSURE VALVES REPLACED.