As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TRANSIT CHECK, DETECTED BOTH RADIO ALTIMETERS WITH FAILURE. MAINTENANCE PERSONNEL PERFORMED FIM DMC-B787-A-25-34-33-02-00A-520A-A PROCEDURE, CONFIRMING THE FAILURE. BOTH L AND LRRA ANTENNAS WERE REPLACED AND THE OPERATIONAL TEST AND PERFORMANCE RUN TEST WITH BOTH ENGINES WERE PERFORMED IAW AMM DMC-B787-A-25-34-33-02-00A-520A-A AND DMC-B787-A-34-33-02-00A-720A-A, ALL TESTED CORRECT.