Hi everyone, I experienced similar problem with my Nokia Lumia many times. This might be happening due to loose battery or some other issues with battery like low charge. Just you need to do some basic steps. - Take out battery for some time and reassemble after a couple of minutes ( May need small paper packing if it is loose) - Restart with patience May have to repeat this a couple of times. (1) this will definitely work otherwise go to Mobile techie. Thanks for your patience.