I replaced the battery in my Sony NW-A3000 with a brand new one, carefully following the manual instructions but now it won't charge. It starts up with the welcome text , then the spinning disc icon appears and that's it. I can hear something whirring inside then it stops, then starts, stops, starts etc. over and over. The red light on the charger flickers faintly whereas before it shone brightly when charging. What's going on?