As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FO FMC WENT BLANK @2233Z FOR LESS THAN 10 SECONDS BEFORE RESTARTING. NO LINGERING EFFECTS NOTED. A/C IN CRUISE @ FL340. .79 MACH VMC. GROUNDED - YES. CONDUCTED FMC OPERATIONAL CHECK REF B737-900 FIM 34-61 TASK 836 ITEMS A-E. NO DISCREPANCY NOTED.