What was found
DURING CRUISE IN OCEANIC AIRSPACE, BOTH FMC'S FAILED THEN RECOVERED. GROUNDED - YES. PERFORMED #1 AND #2 FMC BITE/IN FLT FAULTS FOUND FMC-L PMG FAULT AND A CORRESPONDING FMC-R RESYNC WITH SAME TIME STAMP. L/H FMC WAS ONLY RESET/FAULT ON LEG 1 R/H FMC RESET WAS DUE TO L/H FAULT. PERFORMED FMC -L & R OPS CHECK. NO DEFECTS NOTED REF B737-800 AMM 34-61-00-710-801 & FIM 34-61 TASK 837. ETOPS SIGNIFICANT SYSTEM GROUND VERIFICATION SUCCESSFUL.