If the motor runs, then the problem is in the PCB.
Easiest way to test is to power the motor with a car battery or a battery charger. This is a direct replacement wire feed motor for the following Snap On Models - FM140A YA212A Muscle Mig 250SL If your wire feed motor is not running, it could be the motor or it could be the Circuit Board. Brand new wire feed motor which is a direct replacement for Snap-On p/n SN138C24. If your wire feed motor is not running, it could be the motor or it could be the Circuit Board. This wire feed motor fits ONLY the following Snap-On Welders: FM140A YA212A MM250SL. Location: Elk Grove Village, Illinois, US,