@alex_79 instructions were followed as per the 2600 jr specific parts of the included UAV guide, but yes - there is nothing indicating variations in jumpers for 2600 models or for a PAL B jr. I don't have the expertise to know more than the guides for these sorts of products. I have a rudimentary understanding of electronics, and can solder, desolder, replace through-hole style components, perform basic testing etc, but I'm not sure where to start on tracing functions.
I'll try reaching out to the The Brewing Academy for extra guidance also.