As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE CREW REPORTED THE NR 2 ENGINE TORQUE BECAME ERRATIC WITH FAST SURGING AND PLUS OR MINUS 5 PERCENT WHILE ON CRUISE. CREW ELECTED TO RETURN TO DEPARTURE AND LANDED WITHOUT INCIDENT. ACFT REMOVED FROM SERVICE. ADJUSTED GROUND WIRE ON RT TORQUE SIGNAL CONDITIONER IAW 72-00-00. GROUND CHECKED AND NO FLUCTIATION NOTICED AND 77-50-00. ACFT RETURNED TO SERVICE.