In case your headphones is not turning on when you press the power button (no light) :

1. Make sure your battery is charged 

2. If you're certain that your battery is charged, your headphones are probably stuck and need to be rescued/reset. 
Try to put it in "Rescue Mode"

3. In case "Rescue Mode" is not working, try to "Force Update" 3D Sound One.

In case your headphones are still malfunctioning, please reach our support team by creating a ticket on the Help Center or by email at