As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA FLIGHT: 5 MINUTES TO LANDING, RED -FAIL- MESSAGE APPEARED IN NR 1 VHF FREQUENCY SELECTOR BOX ON BOTH ARCDU'S. USED NR 2 COMM TO LAND. RAN CHECKLIST AT GATE. FAIL MESSAGE RE-APPEARS. MAINTENANCE POWERED OFF AIRCRAFT. THEN RE-APPLIED POWER. SYSTEM OPS CHECKS GOOD. NO FAULTS WERE PRESENT ON NR 1 R/T. PERFORMED OPS CHECK OF THE NR 1 VHF COMM SYSTEM IAW Q400 AMM TASK 23-11-00-710-801. OPS CHECKS GOOD. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.