As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MOMENTARY LOSS OF BOTH FMC FAIL ON BOTH CAPTAIN AND FIRST OFFICER SIDE. SYSTEM RESTORED ITSELF BEFORE QRH PORCEDURE WAS STARTED. GROUNDED - YES. DEU 1 & 2 LOGGED NO FMC 1 DATA, ONE FLIGHT COMPLETED FIM TASK 31-63 TASK 809 NO INPUT FROM LRU ON 429 BUSS DEU 1&2 NO CURRENT FAULTS. NO1 FMC OPS NORMAL PER B737-900 AMM 34-61-00.