Hi, my line 6 FBV shortboard mkII has been acting up recently, and won't even calibrate. First it started out as I would be in tuner mode, and when I went out of tuner, it was randomly switch back to the tuner mode while I was on one of my A-D channel banks. And now, i unplugged it, and won't even calibrate. If someone has had this problem and has fixed it, or someone just knows how to fix it, that would be awesome if you could help.