As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING DESCENT INTO BNA THE CREW REPORTED NAV 1 AND 2 BOTH FAILED AND THE RMU NAV 1 AND 2 BOXES INDICATED DASHES. THE AIRCRAFT DIVERTED TO SDF WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REPLACED BOTH NAV 1 AND 2 UNITS WITH NO FURTHER DEFECTS NOTED. (NAV COMPUTER NR 2 P/N: 7510100-631; S/N: 03087150; TSN: 12755; CSN: 9357).