I just bought a Sonsa Clip+ and I cannot turn it on/off using the little round power switch at the top. I need help since it is the clip+ there is no slide button
Try holding the button down for 20-30 seconds and then see if that sets things aright.
Also, is it possible the player needs to be charged? If so, try charging it for 3 hours or so.
If neither helps, I’d exchange it for a new player.