As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOS - FLT 6433 - DURING FLIGHT, NR 1 COMM FAILED AND FLIGHT CONTROL HAD THE AIRCRAFT RETURN TO BOS. BOS MAINTENANCE CLEANED THE CONNECTORS ON THE R/T UNIT AND PERFORMED GROUND CHECKS. ALL CHECKS WERE GOOD AND THE AIRCRAFT RETURNED TO SERVICE. (X)