As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 6455 - IAD-PHL - DURING TAXI, AIRCRAFT RETURNED TO GATE DUE TO NR 2 SYMBOL GENERATOR FAILURE. MAINTENANCE INSPECTED AND REMOVED AND REPLACED SYMBOL GENERATOR, OPS CHECK OK. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (M)