What was found
CLIMBING THROUGH 17,000 FEET, LOSS OF ALL PRESSURIZATION, CABIN CLIMBED TO 14,000 FEET. NO CONTROL IN ANY MODE. INITIATED DESCENT TO 9,000 FEET. CABIN ALTITUDE CAUGHT AIRCRAFT ALTITUDE, STILL NO CONTROL OF PRESSURIZATION, RETURNED TO BDL. GENERATED FROM PILOT REPORT. REMOVED AND REPLACED SAFETY VALVE IAW 21-30-51. OPS CHECK ON GROUND GOOD. (X)