As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: FLIGHT DECK DOOR WOULD NOT OPEN FROM INSIDE THE FLIGHT DECK IN FLIGHT. OPENED AT THE GATE BY MOVING FLIGHT DECK DOOR SWITCH TO UNLOCK POSITION. REPLACED FLIGHT DECK DOOR LATCH MECHANISM PER AMM 52-51-21. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED.