As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE CAPTS MAP DISPLAY SHOWED VTK. BOTH CDU'S WENT TO MENU PAGE. AFTER 30 SECS CAPT LOST LNAV/VNAV. ALSO HAD SINGLE FMC OPS IN SCRATCHPAD. BEFORE I COULD RUN THE CHECKLIST IT FIXED ITSELF. GROUNDED - YES. RIGHT FMC LOGGED LEFT FMC PRES POS LAT RATE FAULT. NO DEFECTS NOTED. FMC'S OP CK NORMAL. REF FIM 34-61 TASK 837 & 801.