Mp3 was working, then it stopped

Question

After adding new songs to my mp3 player I unhooked it and took it into my room.It said that it was still connected to the USB although everything was completely unhooked.To try and fix the problem I hooked it back up think that maybe the songs hadn't completely finished downloading to my mp3.It then wouldn't show any connection at all.I unhooked everything again and my mp3 player wouldn't turn on at all.NO SE PUEDE PRODUCIR