Alright, so, I've been working on this mod for a long time, and I keep coming up with problems. I'm now onto trying this with my second Dreamcast, and I've had this problem with both of them, and the exact same problem at that, but maybe this isn't even a problem at all. I've been testing as I go along to make sure everything is working. I'll get the audio working, then I'll get the switch working, however, once I solder the H-Sync and the V-Sync and then the three red, green and blue signals, I stop outputting any video other than VGA (as far as I can tell, as I haven't finished exactly, but I don't know what else it would be doing). Now, I haven't proceeded past this point yet, because, I don't understand why this would happen. Do I need to actually finish? This puzzles me, because I don't see why it would stop outputting any other signal. Just because I've put wires to those points, shouldn't change anything, I shouldn't have to finish to get any other kind of signal, right? Note: I am still getting sound when I do this.
Edit: Found my problem after a lengthy trial and error...maybe found an easier way to do the mod as well...