As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CAPTAINS MCDU DEP/ARR AND HOLD BUTTONS INOP. GROUNDED - YES. PERFORMED B737-800 FIM 34-61 TASK 802-VERIFIED CAPTS MCDU DEP/ARR AND HOLD BUTTONS FAILED/INOP. REF B737-800 AMM 34-61-01,REPLACED CAPTS CDU. INSTALLATION OPS TEST PASSED. CAPTS MCDU DEP/ARR AND HOLD BUTTONS OPERATE NORMALLY. VERIFIED SOFTWARE 3463-SM1-02 CONFIGURATION, OK FOR SERVICE.