As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 3959 THE FLIGHT ATTENDANT REPORTED THE MAIN CABIN DOOR WAS DIFFICULT TO OPEN. THE AIRCRAFT WAS REMOVED FROM SERVICE. LUBRICATED MAIN PASSENGER DOOR ROLLERS PER AMM 52-18-00. NO DEFECTS NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.