As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
COMM NR 1 WORKED ON THE GROUND BUT SHORTLY AFTER TAKE OFF COMM NR 1 DID NOT WORK ON CAPT OR F/O SIDE. RETURNED TO FIELD. REMOVED FROM SERVICE. PERFORMED A GVI OF NR 1 VHF COMM ANTENNA. NO DEFECTS NOTED. TESTED POWER OUTPUT AND REFLECTED POWER WITH WATT METER. ALL CHECKED GOOD. REMOVED AND REPLACED NR 1 VHF COMM MODULE, PER AMM 23-12-01-000-801-A AND 23-12-01-400-801-A. ALL CHECKED GOOD. MODULE REPLACED AS A PRECAUTIONARY MEASURE. AIRCRAFT RETURNED TO SERVICE.