As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON CLIMBOUT WITH BOTH PACKS ON CABIN BEGAN TO CLIMB TO 10,000 FT. STARTED A DESCENT, A/C REMAIN UNPRESSURIED UNTIL LAND. *S/D* REMOVED AND REPLACED LT PACK VALVE. OPS CK OF BOTH PACK LT & RT PRESS. AC NORMAL ON GROUND AS PER MM. REMOVED PLACARD.