As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOTH FMC'S HAVE FAILED OR FMC SELECTOR IS IN L WITH THE LEFT FMC FAILED OR IS IN R WITH THE RIGHT FMC FAILED. RIGHT CONTROL DISPLAY UNIT (CDU) FAULT. EMERGENCY DECLARED. SWAPPED CDU FROM F/O POSITION TO CENTER POSITION DUE TO FAILURE OF F/O CDU. REPLACED CENTER CDU AND OP CHK GOOD REF AMM 34-01-02.