As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT FMC FAILED DURING CRUISE AT FL300. CAPT'S ND SHOWED VTK FOLLOWED BY LOSS OF LNAV AND NO FMC DATA ON BOTH CDU'S. FMC CAME BACK ON WITHOUT MOVING FMC SOURCE SELECT SWITCH IN LESS THAN 90 SECONDS. GROUNDED - YES. ACCOMP'D B737-900 FIM 34-61 TASK 836, L&R FMC OPS NRML - NO CURRENT FAULTS. NO HISTORY LAST 30 DAYS. ETOPS SIGN'F SYSTEM - GND VERIFICATION SUCCESSFUL. SEAMC ARNIE NOTIFIED.