What was found
WHILE PASSING THROUGH FL230 CABIN ALT WAS NOTED TO BE APPROX 10,000 FT AND CLIMBING 1,000 FT/SEC. A/C LEVELED AT FL230 WITH CABIN CLIMBING. DESCENDED A/C AND SWD TO MAN DC CONTROL. OUTFLOW VLV INDICATED FULL CLOSED. MAN CONTROL CLOSED ONE MORE NEEDLE WIDTH TO FULL CLOSED AND CABIN CONTROL WAS REGAINED. WHILE T/S FOUND CK VLV AND HP REG VLV BAD, NR 2 ENG. BOTH ITEMS REPLACED AND PERFORMED CK OUT PER MM 21-11-0 PG 504. ALL OPS AND INDICATIONS NORMAL.