How to Troubleshoot & Replace Whirlpool AP6020664 / WPW10380496 Motor Brush

God Bless Youtube! Searched "replace motor in Kitchen Aide mixer" and found an excellent tutorial on the subject made by AppliancePartsPros.com. Followed the instructions with my smart phone and purchased a new motor and brushes. Fixed the $500 mixer for $50.. Runs like new but now have to change the color per her request. Excellent company to deal . 

Watched few videos. Found that worm gear can be faulty. Opened the mixer and replaced it after it was received. However, the mixer was stillnot working. Replaced the carbon brushed, which were worn out. Mixer is now working after few adjustments to the speed controller scres at the back of machine. Cost me about $ 30.00 and two hours of work time. 

I ordered the armature and field-asm cause I did a test on the armature by connecting it directly to the power line and did not have any movement. Upon changing the armature and assembling the brushes, I realized one of the brushes was getting held up. I opened up the edges of the brush holder and that did it. I knew nothing seemed wrong with the parts I took out so I concluded that was the problem because I had just bought it, used it only twice and it stopped working. 

First I ordered a Speed Control Plate and installed it. This made no difference even doing the recommended adjustments to screws. I went back to the website and read more comments and decided to order the Phase Control Board and the Speed Governor. After installing all of these speed control parts, it ran like a brand new machine. Thanks for the great videos that gave me the confidence to tackle this repair myself. I bought new brushes just for backup and the stock was running low. 

I used these parts in a totally different project, not related to a mixer. i just needed an inexpensive set of small commuter brushes to make contacts. 

Replaced winding and armature 

Inspected the brushes and they were about 1/4", replaced and all speeds worked perfectly. (Orientation of the flat side is important, Left is upper left and Right is lower right) 

Replaced the brushes. completed 

I replaced both brushes. 

Wife dropped something into the bowl jamming the mixer. The "retaining pin" sheared off, as designed. Easily found the parts in the schematic provided. Parts came in almost overnight (unbelievable!!!). Everything went back together as expected and the mixer is working again. Incredible first experience for me working on an appliance like this. AppliancePartsPros could not have made my job easier. Amazing customer service.