Headset not powering on

First, try changing the cable or testing it with another device to ensure it works. If not there is a pinhole under the ear cushion (non-mic side) that has a reset button. Use a paperclip to press down into it to reset the 9X. You should feel a circular bump which is the button. If this doesn't fix it, download the SteelSeries Engine from https://steelseries.com/engine to a desktop/laptop and update the headphones.