As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CAPTAINS MCDU'S L2 SELECTING BUTTON IS INOP. THIS IS THE SECOND BUTTON FROM THE TOP ON THE LEFT SIDE OF THE CAPTAINS MCDU. THE CAPTAINS MCDU IS OTHERWISE COMPLETELY OPERATIVE JUST THE L2 BUTTON IS INOP. REPLACED NR 1 MCDU AND KEYBOARD REF MM 34-61-01, OPS CHECK NORMAL.