As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB OUT OF BOS THE CREW REPORTED A PTRIM MAIN INOP MESSAGE ON EICAS. THE QRH WAS FOLLOWED AND THE FLIGHT RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS THEN FERRIED TO SDF FOR FURTHER TROUBLESHOOTING. WHILE TROUBLESHOOTING THE FAULT IN SDF, MAINTENANCE FOUND THE HORIZONTAL STAB ACTUATOR MOVING SLOWLY AND MAKING NOISE. THE HORIZONTAL STAB ACTUATOR WAS REPLACED AND NO FURTHER FAULTS WERE FOUND.