Good night. You must open your blender. Then the first thing will be with a multimeter based on continuity, test if the cables that go from the electrical outlet and reach the internal socket of your blender are in good condition, this you do with the equipment unplugged. Also with some skill, you can try the swicher where it turns on and you give speeds to your blender. If you pass those tests, check the carbons in the engine Also, many motors have on their winding a component that is a thermal resistance, which is usually damaged, but this would be the last thing to check. Luck