As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CLIMBING THROUGH FL 220 PRESSURIZATION FAILED CABIN ALT CLIMBING RAPIDLY, NO FLOW HIGH. FOLLOWED QRH LED TO DEPLOYING PAX O2 MASKS. R & R NR 1 & NR 2 PRESS CONTROLLERS IAW MM 21-32-03. R & R ONE EACH PRESS CONTROLLER LINE ON NR 1 PRESS CONTROLLER IAW MM 21-32-00. PERFORMED SYS LEAK CHECK IAW MM 34-11-00 & IAW LOG PG 485750 FOR RE-STOWING OF PAX O2 MASK'S & PANELS IAW TASK CARD I0583501.