I have a kenwood KMx 50 mixer & it has a speed
KMX50 would start and accelerate to high speed, then slow down some with fairly erratic speed. I tried changing the triac on the main speed control board, then also the whole board (£45). It made no difference.
The only other component I realised it might be was the speed control board which is on the rear end of the motor under the main cover (I found this component on a site selling Kenwood parts, and was where I got the main board from, which is how I know it's speed control). When I inspected it I found two of the terminals broken. You had to look very closely to see they were broken. It's a poor design as the three legs of the terminals are quite long, and very thin, so on high speed when kneading there is much vibration, which is why I suspect the terminals broke. I cut them back just enough to resolder. The component isn't quite fully inside the sensor wheel on the motor shaft, but it still picks up sufficient signal to control the speed and now works fine. Haven't tried it under load yet, but no reason to think it won't work correctly. So check this before ordering a £45 board!
on May 16, 2019