I don't know what causes this problem, but my tone knob isn't really working. I've only had this guitar for less than a week, so not really acquainted with it yet. But the tone knob seems to only sporadically engage the tonal change, and sometimes it just won't work. Here's a demonstration video: You can see/hear after the 40 second mark, when I pick the strings and turn the knob, the tone just doesn't change. Sometimes it does. It actually worked surprisingly well here on this video. Anyone have any idea why this is?