As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT THE GATE, THE 2L DOOR WOULD NOT OPEN. MAINTENANCE FOUND THE DOOR ASSIST ABOTTLE DISCHARGED ON CLOSED DOOR PRELOADING ON CLOSED DOOR PRELOADING DOOR MECHANISM. THE PRESSURE WAS RELIEVED AND THE DOOR WAS OPS CHECKED,OK. THE DOOR ASSIST BOTTLE WAS THEN SERVICED.