As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IMMEDIATELY AFTER TAKEOFF OUT OF RDU, RECEIVED A SMOKE CAUTION LIGHT ON EQUIP COOLING PANEL. STATUS MESSAGE OVERBOARD EXHAUST VALVE OPEN AND LEFT RECIRC FAN INOP LIGHT. CREW ELECTED TO RETURN TO RDU. CONTRACT MTC FOUND BAD SMOKE DETECTOR. REPLACED DETECTOR AND ALL CHECKED GOOD.