If the furby does not move and just constantly shuts down, then the the small 6V brushless DC motor went wrong. I had the same issue. You can replace it with one from a PC DVD reader (this is the door opener motor). Shaft is smaller but it's ok, diameter is good. You need a solder iron as well to replace electronic part from DC motor. If the furby does move, then there might me a sliced wire or a barely plugged in wire. I recommend you taking it apart, these newer furbys are harder to take apart, here’s a guide: https://learn.adafruit.com/furby-2012-teardown