As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER POWER INTERRUPTION DURING PREFLIGHT "FMC DISAGREE" MSG ON INBOARD DISPLAY. GROUNDED - YES. RMVD & RESET POWER TO BOTH FMCS BY PULLING/RESETTING 4EA FMC C/B'S. L & R FMC OPS NML REF B737-9 AMM 34-61-00. FMC DISAGREE MSGS EXTINGUISHED IN CAPT & F/O DISPLAYS.