1) Try to open a sheet music and check whether the connection icon at the top left corner of the screen is red or green. Green means connected and red means not. If it is red, please check the cable or Bluetooth connection again.3) Try another smart device, if the connection also failed, then it means the cable was damaged, you would need a new cable. You can purchase it from here:  https://theonemusic.com/collections/piano-accessories/products/keyboard-piano-cables. (Please note other brand's cable does not work with our pianos)