What is that certain part? Coz there are 2 parts in the game where you can't see what's happening on the screen. both of them are fights with bosses(first one with the girl after you defeat some kind of beast and the second with the man after you defeat the cat - if I'm not mistaken). You just have to rely on luck and save and hit the A button very often and to reload your savestate if you don't hit her or him and so on.
P.S. Sure you can try to use 1964, but it won't help you at all. I think I've already tried Tsumi to batsu on the 1964(Pj64 savestates from the places where there is no picture, if I remember it right).