September 20, 2015

How to replace a stand mixer phase control board

By Lyle Weischwill
How to replace a stand mixer phase control board

This DIY repair guide gives instructions for replacing the phase control board in a stand mixer. The phase control board works with the governor and control plate to control motor speed. If the mixer won't run or doesn't maintain the set speed, the phase control board could be the problem. Replace a malfunctioning phase control board with the manufacturer-approved replacement part.

This repair procedure shows how to replace the phase control board in KitchenAid and Whirlpool stand mixers.

Quick links
Tools required
Work gloves
Wrench set
Shop towel
Needle nose pliers
Phillips screwdriver
Repair difficulty
Time required
30 minutes or less
Repair difficulty
Time required
30 minutes or less
How to replace the phase control board in a stand mixer repair guide video.

Replacing a stand mixer phase control board video.

Instructions

  1. 01.

    Shut off the electricity

    Unplug the power cord.

  2. 02.

    Remove the end cover

    Remove the end cover mounting screw and pull off the end cover.

    Remove the end cover screw.

    Remove the end cover screw.

    Remove the end cover.

    Remove the end cover.

  3. 03.

    Disconnect the wires from the control plate

    Take a digital photo of the wires connected to the control plate to document their location. Disconnect the wires from the control plate.

    Remove the control plate wires.

    Remove the control plate wires.

  4. 04.

    Remove the control plate

    Carefully disconnect the spring from the bottom of the control plate and hook the spring onto a shop towel to prevent the spring from sucking back into the upper housing.

    Loosen but don't remove the jam nuts on the control plate upper mounting screws.

    Unscrew and release the control plate upper mounting screws from the upper housing mounting posts.

    Pull the control plate off.

    Disconnect the spring.

    Disconnect the spring.

    Hook the spring to a shop towel.

    Hook the spring to a shop towel.

    Loosen the jam nuts.

    Loosen the jam nuts.

    Remove the top screws.

    Remove the top screws.

    Remove the control plate.

    Remove the control plate.

  5. 05.

    Remove the phase control board

    Remove the phase control board mounting screw and pull off the phase control board.

    Remove the screw.

    Remove the screw.

    Remove the phase control board.

    Remove the phase control board.

  6. 06.

    Install the new phase control board

    Position the new phase control board in the upper housing and reinstall the mounting screw.

    Install the new phase control board.

    Install the new phase control board.

  7. 07.

    Reinstall the control plate

    Position the control plate in the upper housing and line up the upper mounting screw holes.

    Reinstall the upper mounting screws. Tighten the screws evenly until 3/8-inch of the screw remains visible.

    Leave the jam nuts loose until you check and adjust the mixer speed in a later step.

    Reinstall the spring on the bottom of the control plate.

    Reinstall the control plate.

    Reinstall the control plate.

    Reinstall the stop screws.

    Reinstall the stop screws.

    Reinstall the spring.

    Reinstall the spring.

  8. 08.

    Reconnect the control plate wires

    Using your digital photo as a guide, reconnect the wires to the control plate.

    Reinstall the control plate wires.

    Reinstall the control plate wires.

  9. 09.

    Reinstall the end cover

    Position the end cover on the upper housing and line up the screw holes. Reinstall the end cover mounting screw.

    Warning: Do not pinch any wires when reinstalling the end cover.
    Reinstall the end cover.

    Reinstall the end cover.

    Reinstall the screw.

    Reinstall the screw.

  10. 10.

    Restore power

    Reconnect the power cord.

  11. 11.

    Check and adjust the speed control

    Hold a finger next to the beater shaft to count revolutions.

    Start the mixer at stir speed.

    Count the orbital revolutions of the beater shaft for 15 seconds. At stir speed, the beater shaft should hit your finger 15 times indicating that the shaft is spinning at 60 RPM.

    If the mixer is spinning too fast, unplug the mixer and evenly rotate the control plate upper mounting screws in. Rotate the screws out to increase speed.

    One full revolution of the screws adjusts the speed about 5 RPM.

    After adjusting the speed, reassemble the mixer and test the speed again.

    Continue adjusting and checking the speed until the mixer runs at 60 RPM at stir speed.

    Once the correct stir speed is set, unplug the mixer and tighten the jam nuts on the control plate upper mounting screws.

    Reinstall the end cover and restore power.

    Check beater orbital speed.

    Check beater orbital speed.

    Adjust mixer speed.

    Adjust mixer speed.

    Reinstall the end cover.

    Reinstall the end cover.

    Reinstall the screw.

    Reinstall the screw.

Warning: Undertaking repairs or maintenance to appliances or power equipment can be hazardous. Should you choose to undertake repairs or maintenance, you are assuming the risk of injury to your person or property. In an effort to reduce the risk, use the proper tools and safety equipment noted in the applicable guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs or maintenance, however, should only be performed by a qualified technician.

Symptoms common to all stand mixers

Choose a symptom to see related stand mixer repairs.

Main causes: lack of electrical power, wiring failure, worn carbon motor brushes, bad drive motor, tripped overload switch, control problems
Main cause: worn carbon motor brushes
Main cause: attachment clearance setting needs adjustment
Main causes: phase control board failure, wiring connection problem, faulty electronic control board
Main causes: bad wiring connections, faulty speed control plate, electronic control board failure
Main causes: bad worm gear, damaged planetary gear assembly
Main causes: bad lubricating grease, mixer sitting idle for weeks at a time, mixer running constantly for more than 30 minutes

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