As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS ON TAKEOFF AFTER LIFTOFF AT APPROX. 400" AGL, A/P #1 WOULD NOT ENGAGE, CAPTS MCDU SCREEN BLANKED THEN WENT TO AOC INDEX MENU PAGE. CAP'TS ND DISPLAYED "MAP LOST" MESSAGE. F/O REVERTED TO OPEN CLIMB. ALL INDICATIONS RETURNED TO NORMAL IN 10-15 SECONDS WITHOUT PILOT ACTION. MAINTENANCE REPLACED FCU IAW AMM 22-81-12. OPS TEST IS NORMAL IAW AMM 22-96-00.