How to test phase board. thx

Here's a link for a Service Manual which applies to your mixer. While the motor works as you have stated, you might wish to test the motor's stator, and if that is all right, test the armature. There is plenty of information on armature testing on line.

http://www.kitchenaidparts.eu/documents/pdf/service-manual/classic-svc-manual-new-email-version.pdf

First check the simple things, are the brushes in properly, they are keyed to only fit properly one way. Look in the hole with a torch and line the missing corner up with the blocker right inside. If you have fried something it could be damaged switch contacts on the black control plate or even weaker would be the phase board at the top just under the back cover. Testing for circuits with a multi meter will prove everything except the phase board. If you have circuits everywhere they should be then change that board.

You really need to get a Multi meter and follow the power, you have replaced the phase board so we can probably discount it being that.
First check that the switch contacts behind the black control board are really touching when you move the speed control lever to turn the mixer on.
Next the cable, do you have continuity from the wall plug to the control board on phase & neutral, (Check green earth wire as well for the sake of safety) that will be the black wire and the white wire on the 2 lower plug in contacts on the black control board at the back.
Next remove the carbon brushes, do they have reasonable length and most importantly are they fitted correctly with the corner key aligned with the blocker at the bottom of the brush holder.
Next with brushes out check for field winding continuity. On the other side of that black control board to where the power comes in there will be a red wire and a white wire that disappear into the motor housing. One of the wires will have a circuit to one of the brass brush holders and the other wire will have a circuit to the other brush holder. The resistance of both of those circuits should be pretty much identical.
After you have done those tests you should begin to have a clue as to where the problem lies.

The first thing you need to do is remove the end cover on the mixer, there is a screw at the top you need to undo then in an upwards motion you should be able to pull that off. behind there is the speed control plate. there are two screws at the top, and one at the bottom, the two at the top need to be adjusted the same amount, to speed up the mixer you turn the screws out, to slow down, you turn them in. you want to do each screw 1/4 turn, then test the mixer, see if this will slow the mixer down, so it regains the other speeds. If this adjustment does not work, then the problem will be the phase control board, that is part number W10325124, we sell the board, here is a link to that on our website: http://www.mendingshed.com/kaphaseboard.html.

Also, here is a link to the service manual for your mixer, it will go into more detail on taking the back cover off, and adjusting the speed control plate. Also if you do end up needing to replace the phase board it will show you how.

Service Manual: http://ep.yimg.com/ty/cdn/mendingshed/kitchenaidservicemanual.pdf

If you have any questions feel free to call us.

Colleen
The Mending Shed
801-225-8012

Check for safety micro switches if you have already checked for power at the phase board

If your mixer only runs on high speed there are 3 things that can cause that. The first thing to check will be the speed control plate, Remove the trim and end cover on the mixer, the first thing you should see is the speed control plate, this has 3 screws on it, try adjusting the top two screws 1/4 turn, this should slow the mixer down, do not over tighten. Also check to see if the control plate spring is unhooked. If the spring is unhooked, attach to bottom of the control plate, and squeeze the spring end.
If this does not fix your mixer, check the wiring of the mixer, you can locate a wiring diagram on the last page of the service manual.
If the speed control plate is adjusted correctly and all the wiring is correct it will be your speed control phase board. You can test the speed control phase board to see if it is shorted. With the line cord disconnected, pull the t-b ar contacts to open, and insert a piece of paper between them so they cannot close. Reapply power-the mixer should just run or buzz trying to run. If it operates at full speed, teh phase control board is defective and needs to be replaced.
Here is a link to the service manual: http://lib.store.yahoo.net/lib/mendingshed/kitchenaidservicemanual.pdf
This will aid you in taking the mixer apart, troubleshooting and putting it back together, remember the wiring diagram is the very last page.
Thank you,
Colleen
Customer Service
MendingShed.com
800-339-9297

I am sorry to say but only with a new one, about 30 bucks and five minutes of work, but if your mixer has any speeds working except only high (only high means it is the phase control board) then it is more likely the speed control board is bad rather than the phase board. Can you send is more info on what happened when the mixer started or stopped working. We can be of more help with more info

You can purchase a new Power Phase Control Board (30)
on eBay for $25.00

It sounds like you need a new speed control phase board:
http://kitchenaidmixerspares.co.uk/SearchResults/tabid/37/Default.aspx?Search=phase

Hiya,

Sorry you are experiencing an issue with your appliance. It would appear you need to replace your phase board. Please see one of the links below to assist you. Please note the videos show how to replace 230V phase board. The steps are the same for 110V. Please make sure you have the correct part for your appliance.

https://www.youtube.com/watch?v=era-Dp5P8Xw
https://www.kaparts.co.uk/Help/KitchenAidHelp/KitchenAidMixerHelp/KitchenAidReplacingyourphaseboard230volt/tabid/613/Default.aspx