Are you using an HDTV, if so that might be the issue as av does not work to good on HDTV’s, I know this because of my SNES, NES, and Genesis that break up badly without a converter box. Although a converter box is not really the best solution as in many cases it breaks up the audio and you get random lines through games. That’s why its better to have a CRT for older consoles as HDTV’s don’t handle these things well.