A:Answer To power on the headphones, hold the round button in the center of the three. Hold until you hear the device say “Power on; ready to pair,” and if you’d like to enter pairing mode, continue holding the button until you hear “Pairing.” As for your aux cord, make sure that the cord isn’t stuck in the headphone jack. If it is, I recommend taking it in for repairs, as the device cannot be powered on while in aux mode.