A problematic cone set would cause jammed handle feel as well as the annoying sound every time you hit a the disc brake hard or hit a pothole. It makes you feel that something is loose in the handle. You can check the detailed difference between the new and faulty cone set in the image provided in the following link.

http://nexgenbikes.com/site/2011/03/08/how-to-identify-a-faulty-ball-racer-steering-handle-bar-bearing/