As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRESSURIZATION WORKED NORMALLY UP TO FL 310 BETWEEN FL 310 AND FL 320 THE CABIN STARTED TO RAPIDLY CLIMB AT A RATE OF 5500 FPM. THE CABIN BEFORE THE CLIMB WAS AROUND 4000 FT BEFORE THE RAPID CLIMB. THE 10000 FT ALTITUDE ANNUNCIATOR AND MASTER WARNING CAME ON AND AN EMERGENCY DESCENT WAS STARTED. THE CABIN CLIMBED TO 14000 FT. REPLACED PRIMARY OUTFLOW VALVE WITH NEW IAW MODEL 560 MM. 21-32-00. OPERATIONAL CHECK GOOD