No need to go to the driver board. The other lamps in those rows/columns are working so that's not the problem. Check the header pins on the little board that's inside of the stoplight itself. There's a small connector in there, as you've already seen. Remove that little board, and disconnect the connector. Then, reflow the solder on the back of the board to all the pins. Chances are, the one that's used in the yellow light has cracked and isn't making contact. Do the same for the supercharger lamp. I don't remember if this is directly connected to the lamp or if there's a small board as well, but check the solder on there too.