As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRIOR TO DESCENT CAPT SIDE VTK FOLLOWED BY LOSS OF FMC ON CDU, CAPT LOSS OF MAP ON MCDU AND FO LOST FMC ON CDU. PRIOR TO COMPLETING QRH BOTH FMC + MAPS RESET, REENGAGED LNAV + VNAV NO OTHER ISSUES. GROUNDED - YES. C/W FMC RESET PROCEDURE REF B737-800 FIM 34-61 TASK 836 FMC OPERATES NORMALLY. A/C OK FOR SERVICE.