You got a manual, at least a wire diagram? My 78 has power go through this order, that is easy to follow.. battery, fuse, ignition switch, kill switch, coils. Thats an old bike, with points, but you should still have +12V to the coils. Couldn't tell you for sure without seeing a diagram though. Check your fuses, I've seen them work loose. If from there you may have a bad kickstand switch, but if you said it starts with or without stand down, then probably not. Maybe a bad solder joint in the TCI box? Best bet is to get a diagram and a test light or volt meter...