As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE AIRCRAFT WOULD NOT PRESSURIZE AFTER TAKEOFF, A FEW MINUTES AFTER LEVELING AT 9000 FEET THE AFT GALLEY DOOR LIGHT ILLUMINATED. THE AIRCRAFT WAS GROUNDED. PERFORMED PRESSURIZATION CONTROLLER BITE TEST, FOUND A FAULT IN OUTFLOW VALVE. REPLACED BOTH CONTROLLERS AND THE OUTFLOW VALVE DRIVE MOTORS IAW MM 21-32-03 AND 21-32-05.