Hello, So, my trackpad can't physically make a click sound now. It was quite annoying. Then, the problem has solved when I changed to tap-to-click setting. But still, I want my trackpad to be clickable again. Anyone has any idea what happened to the trackpad and way to solve it? I believe the battery has swollen but I'm not sure. It is a 15 inch late 2011 Macbook Pro. Thanks.