As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN SET AT FL 370 AND 6000 FEET, CARGO HEAT OUTFLOW VALVE CLOSED, CABIN CONTINUES TO CLIMB 100 FEET PER MINUTE EVEN WITH RATE KNOB FULL INCREASE AND MANUAL CONTROLLER FULL INCREASE. AIRCRAFT HAD TO BE DESCENDED BELOW FL 280 TO REGAIN CONTROL OF CABIN. REPAIRED SEAL AROUND MAIN CARGO DOOR. OPS CHECK OK ON GROUND PER B727 MM 52-31-0.