As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/RDU - FLT 6431 - DURING TAXI AT 1545 HOURS ON 7-8-97, RETURNED TO GATE DUE TO NR 1 NAV AND NR 1 COM WHEN TRANSFER SELECTED DASHES APPEARED. AIRCRAFT WENT TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND RECYCLED CDU, OPS CHECK OK. AIRCRAFT RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)