What was found
(CAN) APPLICATION OF TAKE OFF POWER - SLIGHT REDUCTION TO TRIM POWER REQUIRED ON NO.1 (96 TO 92%) ,SIMULTANEOUSLY FLICKER OF AUTOFEATHER ARM AND SELECT LIGHTS, SOUND LIKE A FEATHERING, SLIGHT SENSE OF YAW -SPIKE OFF TORQUE ON NR 2 (105% OBSERVED) AND PROP RPM DROP NOTED. APPLIED RTO PROCEDURE AND VACATED RUNWAY. FOLLOWING APPROPRIATE GROUND CHECKS IN ACCORDANCE WITH THE AIRCRAFT`S MAINTENANCE MANUAL, LINE MAINTENANCE INVESTIGATION REVEALED A PROBABLE FAILURE OF THE NR 2 TSCU. THE UNIT WAS REPLACED & FOLLOWING APPROPRIATE GROUND CHECKS THE AIRCRAFT HAS BEEN RETURNED TO SERVICE WITHOUT FURTHER INCIDENT.