As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED A LOSS OF CABIN PRESSURIZATION WHEN CLIMBING THROUGH FL210. CABIN ALT WENT ABOVE 10000 FT DURING DESCENT. MAINTENANCE REMOVED AND REPLACED THE E1 HIGH STAGE AND PRESS OUTFLOW VALVE IAW MM. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT DID A FUNCTIONAL CHECK FLIGHT. AIRCRAFT WAS THEN RETURNED TO SERVICE. (SW21200505705) (K)