The speed control doesn't work well

This problem could be due to a worn or broken speed governor. this part is located on the motor shaft of the unit and works by way of centrifugal force. This however when gone will usually make the mixers speed go up and down, not just one speed. The most likely cause of this problem is the main control board. if this has become faulty, it can make the mixer stop completely or in your case, run full speed when turn on. part number for the board is W10119326. this part can easily be changed by disconnecting all power and removing the back end cover. Once removed make note of the adjustment screws at the bottom of the board. As these are your motor speed adjustment screws, and can be very finely tuned. Once these and the spring has been removed. you can now replace the board. Hope this helps

Thanks

There are points in the back of the mixer which make contact when the mixer is turner on. on my mixer it seemed that the points were not making good contact. Once I moved the bottom tab a little the contact seem to be better and the mixer now worked on all speeds