Last week my old Garmin Edge 200 died. I couldn't switch it on and fitting the charger did nothing. I assumed the battery had failed.
I bought a new 20 Edge - the simplest of all as I don't need mapping, power, cadence Bluetooth or anything technical. It works fine.
Then yesterday I just picked up the old Edge 200 pressed the button and it worked. All the settings and history are still there!