As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE AT FL 290, WITH ANTI-ICE ON & IAS 300, THE PRESSURIZATION FLOW LIGHT CAME ON. ACCOMPLISHED PROCEDURE ON QRH & WERE UNABLE TO STOP CABIN ALTITUDE FROM CLIMBING. DESCENDED TO FL 230 & REGAINED CONTROL OF PRESSURIZATION. EMERGENCY DECLARED, LANDED UNEVENTFULLY. REMOVED AND REPLACED RIGHT ACM IAW AMM 21-51-01 SYSTEM OPS CHECKS NORMAL. NO LEAKS NOTED.