As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 6094, CMH TO BOS. WHILE CLIMBING THROUGH 2,500FT THE CREW RECEIVED A MASTER WARNING PT MAIN FAIL. AN AUTO TRIM FAIL MESSAGE ALSO APPEARED BUT EXTINGUISHED AFTER SEVERAL SECONDS. THE QRH WAS FOLLOWED AND IT WAS DECIDED TO RETURN TO CMH WHERE THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND THE HORIZONTAL STABILIZER ACTUATOR TO BE AT FAULT AND REPLACED IT. THERE WERE NO FURTHER DEFECTS NOTED.