Battery problem ???

Try the firmware upgrade first

Either the device is bad, the pc port is bad, or the software is faulty. Try connecting to different usb port, then a usb port on a different pc with a compatible os. If still not recognized, then there is physical damage to player.

Try this: disconnect the player from the computer, turn it off, hold in the volume + button, and reconnect the player to the computer while holding the volume + button in. Keep holding the volume + button for an additional 5-50 seconds. Windows should eventually go into recovery mode and revive the player- it will pop up a window that says Found New Hardware.
Wizard.