Mixer sparked then stopped. I have replaced the power cord, phase board and brushes are fine. Still won't start. Thinking the armature motor may be fried. I am trying to remove the armature but I can't figure it out. It won't pull out. Even if it isn't the motor, I need to get a better look inside to see if there are any shorted wires. How do I correctly remove the motor armature assembly. Thanks!