It's Proto 2 and the battery is 17 years old! You need a new battery and a good charge. How long do the sounds play once power is killed to the track? Also, try on the DCS forum and ask for GGG. He fixed one of my old MTH engines. Have you lubed the axels and gears and checked for any binding?
That is a really neat engine and I would be reluctant to return it. It should be fixable.
George