What was found
IN CRUISE APPROACHING BKA, WE CLIMBED FL360, AND WE WENT TO REQUEST WINDS AND RECEIVED MULTIPLE FAILURES ( E.G. VTK BOTH SIDES, LOSS OF FMC GUIDANCE, LOSS OF LNAV/VNAV, AND A/T LIR) AFTER A FEW MINUTES, THE FAULTS CLEARED AND ALL NAV DATA IN THE FMCS WERE WIPED OUT. WE RELOADED THE ROUTE, PERFORMANCE DATA AND RESUMED A NORMAL FLIGHT. GROUNDED - YES. PERFORMED B737-900 FIM'S 34-61 TASK 801, 34-21 TASK 801, 22-31 TASK 801, 22-11 TASK 801. DFCS FAULT HISTORY SHOWS FMC-1 SUSPECT. ALL FIM TASKS PASS BITE CHECKS A/C OK FOR SERVICE.