What type of main motor Amp do you have? What error is displayed on the main motor Amp? Encoder faults are not common on LS40 presses. Problems with the main motor brakes also are not common. Belt problems, too loose, oil contamination , etc are common. Encoders are used on Komori's with AC motors. Most of the LS40's have DC motors/drives and common problems are related to the motor brushes wearing too short.