^^ Yeah but that's not the one he's talking about.. I just got a whole stack of those in the other day, and there's a few that have that little board. On the one I have at least, the board isn't even hooked up. It's a small pcb mounted over the heat sink that the hot sits on, with a couple caps, and no wires running to the board at all. I imagine it was so you could hook up maybe some sort of setup to work for gun games or something, I'm not sure.
Some of the boards have that, and use the large voltage regulator. Some of the boards use the smaller voltage regulator. some of the boards are the zenith ones with a remote board, some are the zenith ones without a remote board. The arrangement of the c38 cap is different about 6 or 7 different ways it seems. It's crazy how many different ones they made, most of the parts seem to be the same though except the flyback like you mentioned.