As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO MAINTAIN CABIN PRESSURE WITH ONE PACK. CABIN LIGHT ILLUMINATED SHORTLY AFTER REACHING FL250. LAFT PACK INOP. RT PACK CURRENTLY ON MEL REF DMI# 7827716C. REMOVED AND REPLACED RT & LT FLOW CONTROL VALVES, LH SHUTOFF DIFFERENTIAL PRESSURE SWITCH PER AMM 21-31-2 AND 21-31-9. REMOVED AND REPLACED CABIN PRESSURE CONTROLLER IAW AMM 21-31-2.