As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN, PILOT REPORTED THAT PRESSURIZATION WAS NOT WORKING IN THE MANUAL MODE SETTING ABOVE 10,000 FEET AND THE AIRCRAFT WAS ALREADY ON MEL FOR THE AUTO FUNCTION. MAINTENANCE PERFORMED GROUND OPERATIONAL CHECKS IAW MM 21-30 WITH NO ABNORMALITIES NOTED.