As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FL320 WE HAND A RAPID DEPRESSURIZATION. LEFT PACK WAS 30PSI AND RIGHT 10PSI AND CABIN ALT SLOWLY CLIMBING. CREW DECLARED AN EMERGENCY AND DESCENDED TO A LOWER ALTITUDE. AIRCRAFT RETURNED TO DEPARTURE AIRPORT WITHOUT FURTHER INCIDENT. AIRCRAFT GROUNDED BY MAINTENANCE. MAINTENANCE T/S AS PER FIM 36-10 FT 862 AIR SUPPLY BITE SHOWED HPSOV6 AND HPSOV REMOVED AND REPLACED HPSOV IAW AMM 36-11-07 PERFORMED OPERATIONAL TEST. ENGINE RUN UP AMM 71-00-00 A/C RELEASED ETOPS 180. AIRCRAFT RETURNED TO SERVICE.