Hi, new to here but ive had my octatrack for a while. I love love what this machine can do, but i dont think the build quality is that great as ive had to replace a couple of things on it already!!!. The latest thing to go is the down button, its kind of popped up and no longer works. Anyway just wondering if anyone has had to replace one of these?? is it a simple task?? where did you get a replacement button from?? any help would be much appreciated! thanks