If your MX Keyboard doesn't turn on the keyboard backlight after you wake it up, we recommend updating the firmware using the instructions below:

1. Download the latest Firmware Update Tool from the download page.
2. If your mouse or keyboard is connected to a Unifying receiver, follow these steps. Otherwise, skip to step 3.
   1. Make sure to use the Unifying receiver that originally came with your keyboard/mouse.
   2. If your keyboard/mouse uses batteries, please take the batteries out and put them back in or try replacing them.
   3. Unplug the Unifying receiver and reinsert it into the USB port.
   4. Turn off and on the keyboard/mouse using the power button/slider.
   5. Press any button on the keyboard/mouse to wake up the device.
   6. Launch the downloaded Firmware Update Tool and follow the on-screen instructions.
   7. If your keyboard/mouse still does not work, please reboot your computer and repeat the steps at least two more times.
3. If your mouse or keyboard is connected using Bluetooth and is still paired to your Windows or macOS computer:
   1. Turn off and on your computer's Bluetooth or reboot your computer.
   2. Turn off and on the keyboard/mouse using the power button/slider.
   3. Launch the downloaded Firmware Update Tool and follow the on-screen instructions.
   4. If your keyboard/mouse still does not work, please reboot your computer and repeat the steps at least two more times.
4. If your mouse or keyboard is connected using Bluetooth but is no longer paired:
   1. Remove the Bluetooth pairing from the computer (if any).
   2. Unplug the Unifying receiver (if any).
   3. Launch the downloaded Firmware Update Tool and follow the on-screen instructions.
   4. On the ‘connect receiver’ window, press any button on the keyboard or mouse to wake up the device.
   5. The devices will be connected and the firmware update should proceed.

If the issue persists, please contact our customer support team.