On my 424mkIII the line output, and the Head phone Jack are having probelms. I belive that wiring is lose, and its really annoying. So what should I do to fix the problem?
You can check with Sweetwater Sound as they seem to service about anything.
BUT, I'm sure it won't be cheap -- but, you never know until you call their 800 number--at least the call is free.
Have you tried new cables or another set of cans to see if your wiring is bad? Like plug in and gently wiggle the cables near the connection and away from the plug in and see if you get static and crackles.