Stand Mixer: Why does my stand mixer run on high speed only?

The phase control board helps control motor speed on mixers that use a speed control plate to control the motor. A failed phase control board or a wiring failure can cause the mixer to run on high speed only. On mixers that use an electronic control board to control motor speed, a bad electronic control board can cause the mixer to run on high speed only.

If your mixer has a removable cover on the back end of the motor housing, then the mixer uses a speed control plate and phase control board to control motor speed. Unplug the mixer and remove the back motor housing cover. Check the wire connections between the speed control plate and the phase control board. Reconnect any loose wires and repair any broken wires. If the phase control board wire connections are okay, you'll likely need to replace the phase control board because it isn't helping control motor speed.

If your mixer doesn't have a removable back cover on the motor housing then the mixer likely uses an electronic control board to control motor speed. If your mixer uses an electronic control board to control the motor, unplug the mixer and replace the electronic control board if the motor runs only on high speed.