Screenshot on the Logitech keyboard k400r

Welcome to Logitech Support


Keyboard does not work

If the K400r keyboard is not working, the problem is probably due to a broken connection. The connection between the keyboard and the Unifying receiver can be lost for the following reasons:

  • The battery level is low.
  • The receiver was moved from one USB port to another.
  • The receiver is being used with another computer.
  • The receiver is plugged into a USB hub or other unsupported device, e.g. B. a KVM switch inserted. (Note: It must be connected directly to the computer.)
  • The keyboard is used on a metal surface.
  • Other devices cause radio interference, such as:
    • Wireless speakers
    • Power supplies
    • Monitors
    • Mobile phones
    • Garage door opener

Preparatory steps before connecting the keyboard:

  1. Eliminate or eliminate the above sources of error.

  2. Insert new batteries. (See answer 360023413733 for instructions.)

  3. Turn on your keyboard. (See answer 360023413733 for instructions.)

  4. Be sure to plug the receiver directly and securely into a working USB port on your computer.

  5. Turn the computer on.


Reconnecting the keyboard

  1. Download and install the latest version of the software from the K400r download page.

  2. Start the Logitech Unifying software:

    Windows: Start> Programs> Logitech> Unifying> Logitech Unifying Software

    Windows 8: Start screen> Logitech Unifying Software

  3. At the bottom of the welcome page, click Further.
  4. Follow the instructions on the screen to turn the keyboard off and on again.

  5. If the keyboard is recognized, the following window will appear:



    If you can enter characters in the test field, select Yes and then click Further. Otherwise repeat the instructions from step 4.

  6. click on Completeto exit the Logitech Unifying software. Your keyboard should now be connected.

If this solution doesn't work after a few tries, restart your computer and then try to reconnect.


The keyboard often loses connection

If your keyboard is intermittent and you need to reconnect the Unifying receiver frequently, try the following:

  • Make sure that other electrical devices are at least 20 cm away from the receiver.

  • Move the keyboard closer to the receiver.

  • Connect the receiver to a different USB port on the computer.

Frequently asked questions - FAQs

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