As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT AND RIGHT FMC DISPLAYED IRS GROUND SPEEDS NOT CHANGING. AIRCRAFT BACK TO BLOCK AND GROUNDED, RE-SET RIGHT/LEFT FMC CB'S. RE-ALIGNED IRU'S. OP'S CHECK FMC CONTROL PANEL I/A/W AMM 34-61-02. OP'S CHECK GOOD. DISPLAY NORMAL. AIRCRAFT RELEASED.