As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON FLIGHT 4478 AFTER TAKING THE ACTIVE RUNWAY THE CREW REPORTED THAT ALL ENGINE AND TAKEOFF DATA WENT BLANK. DATA ACQUISITION UNIT 1 FAILS MESSAGE APPEARED ON EICAS. LOST ALL ENGINE INDICATIONS AND LANDING GEAR POSITION INDICATIONS. THE CREW ELECTED TO ABORT THE TAKEOFF. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE NR 1 DATA ACQUISITION UNIT IAW 31-41-01 MM. PERFORMED ALL TEST AND SYSTEM CHECKED GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.