More than likely if it is not turning on and is not charging , and was previously working. Then it is most likely the battery. Lithium batteries need to be stored charged full to 50% if you are going to store them for a long time. If you drain them and then throw them in the closet for a week or two then you will not be able to charge the battery any longer because the battery protection circuit will not allow you to charge when the battery is below a certain voltage. Its a double edge sword the circuit is attached to the battery and is drawing from the battery. So for example you drain the battery dead the headset will cut out when the battery is at 3V. The protection circuit(on the battery) cuts all power to the battery when it reaches 2.8V. You let it sit for a week or so and the circuit will drain down the battery to 2.6V it will not allow the battery to be charged. So long story short keep your rechargeable batteries charged if you plan on not using them frequently. I sell solo 2 and 3 batteries as well as the studio batteries. http://www.ebay.com/itm/292004167074