As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSTALLED NEW FREQUENCY ADAPTERS BECAUSE OF LIFE LIMIT ON OLD ADAPTERS. TRACK AND BALANCE ACCOMPLISHED. SEVEN FLIGHT HOURS LATER, PILOTS COMPLAINED OF VIBRATION. COULD NOT COMPLETE TRACK AND BALANCE ATTEMPT TO MINIMUM IPS. REPLACED FREQUENCY ADAPTER. TRACK AND BALANCE ACCOMPLISHED. NO FURTHER PROBLEMS NOTED.