As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INTERMITTENT DUAL FMC FAIL AT FL 390. LASTED ABOUT 60 SEC THEN RECOVERED. GROUNDED - YES. VERIFIED FMC FAILED R/H FMC PRES POS LAT RATE & L/H FMC HAD CDU R RATE BOTH ARE INTERMITTENT. CYCLED BOTH FMC COMP. ACCOMPLISHED SENSOR STATUS TEST BOTH PASS TEST REF B737-9 AMM 34-61-00-710-002.