As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING TAKEOFF, THE CAPTAIN'S HEADING MODE ROLLED ON THE MULTI FUNCTION DISPLAY UNIT AND THE CREW ABORTED TAKEOFF. THE MULTI FUNCTION DISPLAY UNIT CLEARED ITSELF AND FLIGHT 4191 WAS CLEARED FOR ANOTHER TAKEOFF ATTEMPT. FLIGHT 4191 THEN DEPARTED WITH NO FURTHER INCIDENTS.