As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 320 LAS-ORD - DIVERSION - BOTH A/C PACKS FAULTED / OVERHEATED AT FL 370. DESCENDED TO FL 210 AND BOTH PACKS COOLED ENOUGH TO TURN BACK ON. BOTH PACKS STABILIZED AT HI FLOW/ 170 C. ENGINE HP BLEED ON ALMOST CONSTANTLY EXCEPT IN DESCENT. AIRCRAFT DIVERTED TO PHX. MAINTENANCE FOUND NR 1 PACK PLENUM CHAMBER INNER CHAMBER TORN APART. REPLACED IAW AIRBUS MAINTENANCE MANUAL 21-52-22.