Last night one of my cdj-800s was acting up. I was in vinyl mode and when I pressed the "vinyl mode" button to exit vinyl mode nothing happened, the blue light stayed on and the master tempo button beneath would just blink. Finally i left the vinyl mode pressed and it would get out of vinyl mode but when i pressed it again, the bpm would fluctuate badly! Im fairly new with the cdj800's, so i dunno whats going on. By the way, they are mk1 and I use Serato. Any help would be appreciated, thanks!