As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4123 - DURING TAKEOFF ROLL, AFTER 80 KNOTS BUT PRIOR TO Y1 CREW RECEIVED THE NR 2 REVERSER DISAGREE MESSAGE. TAKEOFF WAS ABORTED. MESSAGE CLEARED DURING THE ABORT. MAINTENANCE REPLACED RELAY K0640. OPERATIONAL CHECK WAS GOOD AND AIRCRAFT WAS RETURNED TO SERVICE. (M)