What was found
DURING CRUISE, VTK AND MAP FAILURE FLAGS NOTED ON FIRST OFFICERS DISPLAY. ADDITIONALLY, "SINGLE FMC OPERATION" WAS DISPLAYED ON FIRST OFFICER MCDU. QRH FOR FMC FAIL WAS CONSULTED AND PER CHECKLIST FMC SOURCE SELECT SWITCH WAS PLACED TO "BOTH ON L" NO RIGHT SIDE (FMC-R) BEARING / DISTANCE ON "POS" PAGE 3. GROUNDED - YES. OMF LAST LEGF INBD FLT DECK EFFECTS FAULTED FMC-R, L/H FMC FAULTED R/H FMC LAST LEG AS WELL. PERF IFIM 34-61-00-810-837. 1 EA C/B ON P6-1 OPENED, TAGGED, UNTAGGED, RESET. R/H FMC OPS RESTORED. ETOPS GND VERIFICATION TEST SUCCESSFUL. SEAMC ETOPS PAT NOTIFIED. FMC XFER SWITCH RETURNED TO NORMAL POSITION.