As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 304 PHX - CLT AFTER TAKEOFF FROM PHX, THE FLT CREW GOT A LANDING GEAR DISAGREE INDICATION AND A LANDING GEAR DOOR OPEN INDICATION. CYCLED GEAR AND STILL HAD INDICATION. RETURNED TO PHX. AN EMERGANCY WAS DECLARED, FLIGHT LANDED WITHOUT INCIDENT. MAINTENACE REPLACED LEFT MLG RETRACTION ACTUATOR.