What was found
FLIGHT CREW REPORTED, COULD NOT CONTROL THE CABIN PRESSURIZATION. RETURNED TO SFO AND LANDED WITHOUT INCIDENT. REPLACED THE OUTFLOW VALVE ACTUATOR. SYSTEM CHECKED NORMAL OPERATION.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
FLIGHT CREW REPORTED, COULD NOT CONTROL THE CABIN PRESSURIZATION. RETURNED TO SFO AND LANDED WITHOUT INCIDENT. REPLACED THE OUTFLOW VALVE ACTUATOR. SYSTEM CHECKED NORMAL OPERATION.