As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT FLT 350 LOST CABIN PRESSURE RECOVERED PRESSURE AT FL 260. DECLARED EMERGENCY FOR THE RAPID DESCENT PROCEEDED TO MXP AT FL200. PERFORM FIM PROCEDURE 21-31-00-101 FIG 103 FOUND FAILURE ON CABIN PRESSURE SELECTOR PANEL. SAME REMOVED REPLACED AND TESTED AS TO AMM 21-31-01-704-014. ALL TEST IS FINE. PRESSURIZATION TEST AS TO AMM 05-51-24-782-001, PERFORMED NO FAULT, NO LEAKAGE. NO OTHER FAULT FOUND.