As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT FO SIDE CDU WENT BLANK FOR APPROX 10 SECONDS, THEN A TEST SCREEN DISPLAYED FOR ABOUT A SECOND FOLLOWED BY A RETURN TO NORMAL CDU OPS. GROUNDED - YES. LAST LEG BOTH FMC'S FAULTED R/H MCDU. RMVD & RPLCD FO'S MCDU REF B737-800 AMM 34-61-01.