What was found
DURING CRUISE AT FL 340, RECEIVED AN FMC P/RST LIGHT ON FWD GLARESHIELD WITH VTK DISPLAYED ON F/O, PILOT FLYING ND FMA DROPPED OUT OF NAV, VNAV PATH TO CONTROL WHEEL STEERING AND NAV DATA DISAPPEARED ON F/O SIDE. SELECTED "A" AUTOPILOT SINCE CA SIDE OK. NO SCRATCHPAD MESSAGE SO WE LOOKED AT FMC DISAGREE & FMC FAIL CHECKLIST. F/O, RIGHT, FMC APPEARED TO SELF-RECOVER AFTER 30-45 SECONDS. PRIOR TO ATTEMPTING FMC ON BOTH LT. ACFT GROUNDED. FMC LOGGED, FMC FAULT IN FLIGHT FAULTS. CDS LOGGED FMC NR 2, DATA INVALID. ACCOMPLISHED FIM TASK 34-61, TASK-836. NO HISTORY LAST 30 DAYS. NO FURTHER ACTION REQUIRED IAW FIM TASK.