I have no idea what to look for as far as a good batch number. When I returned my first 1600, I just didn't want to get another from the same batch which may have been built with a faulty component. Most failures seem to be coming relatively early with this player. I am giving the new one a work out, but the jury is still out on the second 1600 player. So far, it is working great! I don't experience the heat build up that a few other have complained about. My BR player sits in a TV stand that is quite open both in the front and in the back. My TV room is in my basement where it is quite cool if not cold.