As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FLIGHTDECK DOOR COULD NOT BE OPENED INFLIGHT. THE CAPTAIN WAS INTHE CABIN AND WAS UNABLE TO GET BACK ONTO THE FLIGHTDECK FOR APPROX 5 MIN. DOOR WAS ONLY ABLE TO BE OPENED BY PRESSING AT STRIKERS WITH A BALLPOINT PEN. SEEMS LIKE THE UPPER LATCH WAS THE MALFUNCTIONING LATCH. ADJUSTED STRIKER LOCK.