How to fix your Kenmore stand mixer when its motor sparks
Worn carbon motor brushes typically cause motor sparking when you're running the mixer.
Unplug the stand mixer and examine the motor brushes for wear. To remove a motor brush, use a screwdriver to unscrew the motor brush cap. Pull the cap and the carbon brush out. Measure the length of the carbon motor brush to determine its level of wear. Replace the carbon motor brushes if either brush is shorter than 5/16-inch because a carbon brush can cause sparks when it wears down below that length. Replace both carbon brushes at the same time to keep the motor running smoothly and efficiently.
Troubleshooting your Kenmore stand mixer when its shaft isn't spinning
A failed worm wear or damaged planetary gear assembly can prevent the beater from spinning. If the beater doesn't move at all when the motor spins, then the worm gear is likely stripped. Unplug the mixer, examine the worm gear and replace the gear if it's stripped.
If the beater moves around the inside of the mixing bowl but the beater itself doesn't spin, then the pinion gear inside the planetary gear assembly is likely stripped or damaged. Unplug the mixer, pull off the planetary gear assembly and replace the assembly if the pinion gear is damaged or stripped.