I used my pulse bf after some years and it worked at first but then stopped charging and doesnt turn on. Sometimes there's a total black screen and some others this thing appears. My laptop doesnt recognise the device if I connect it. When I used it for the last time some years back it worked perfectly and It has been kept safe since then. No dust, no falls, no nothing. Any ideas? Could it just be the battery? I don't have another to try.