Question about Nakamichi CR-3A?

I am interested in purchasing one of these decks for a really good deal on the net and from what the owner says and the pictures it is in pristine condition exept for one thing,he says when you play a tape the deck stops when it gets near the end of the tape,does anyone know what could be causing that to happen and is it an easy fix or should i stay away from it?Thanks for any help on this..Keith Hugo,Peace.