My Charge 5 will be 3 years old in October, and it died a few days ago. It went from working fine to having an unresponsive black screen. The battery was not depleted but I plugged in the charger anyway. Nothing showed on the screen, but I saw a brief red light flash on the back. Hoping that it was only mostly dead, I let it charge for more than an hour.
None of the reset methods worked, but each time I press the button on the charger, I do feel a vibration on the device. But no lights on the front or back. Calling it dead-dead.
From what I have read, this model only lasts a couple of years, so I guess I got my money's worth. I might see about charging my old Flex, just to track steps, but I won't be buying another Fitbit.
