Hi: Suddenly, a Bachmann 2fn decoder ceased to work. It kept is address as it responded to the light on/off command, but no movement from the motor. The programmer doesn't identify it, even after writing any value to CV 8. I use DCCpp (throttles) and JMRI (programmer). After writing the CV 8 it now doesn't respond to the light on/off command, sure it lost its address. I put it in the programming track and try to write in to CV 8, and it returns -1 which means "verification read fails". My other 4 locomotives work well, the programmer identifies them in case I test that feature. What could have happened?