As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 707 FROM PHX TO MCI, DURING CLIMB OUT AIRCRAFT WOULD NOT PRESSURIZE ABOVE 1.5 PSID. AIRCRAFT RETURNED TO PHX AND LANDED WITHOUT INCIDENT. ON POST FLIGHT FOUND L1 DOOR NOT FULLY CLOSED. OPENED, CYCLED AND RESET DOOR, CONFIRMED L1 DOOR FULLY CLOSED AND LOCKED. NO DEFECTS NOTED. AIRCRAFT RETURNED TO SERVICE.