As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THE NO1 COM UNIT INOP. THE MAINTENANCE TEAM TROUBLESHOT AND FOUND THAT THE COMM 1 VHF-4000 TRANSCEIVER FAILED. THE COMM 1 VHF-4000 WAS REMOVED AND INSTALLED AN OVERHAULED UNIT. THE SYSTEM WAS TESTED AND NO DEFECTS WERE NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE.