As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ISSUE- CAB ALT IMMEDIATELY STARTED TO CLIMB ON DEPARTURE FROM LAS. QRH WAS USED TO VERIFY DIFFERENTIAL PRESSURE. WHILE RUNNING, QRH/CAB ALT REACHED 10,700FT. MANUEL CONTROL IN DN POSITION. CREW REQUESTED TO RETURN TO LAS. NO EMERGENCY WAS DECLARED PER FLIGHT CREW BUT SAFETY VEHICLES DID ROLL. CORR ACTION- R&R'D DIGITAL PRESSURIZATION CONTROLLER OPS TESTED GOOD IN MANUAL AND AUTO.