Shows ID:4100

Connect to power supply, turn on, press reset button (under the power button); you will not loose settings. This is all said also in the manual undet reset.

The reset will NOT make the ID:4100 go away. I had same problem, then I dropped it to the solid ground about 1 feet high (on purpose), and then it works again. Really. I think it is either caused by poor internal connection or anti-shock function that make it cannot access the internal Hard Drive. Or you may try to open it, and try to reconnect the wires interanlly. Try to do it, it won't go worse.