| | Re: Track ball creating problem in down position
As above, it is probably dirt or lint.
Turn the device off. Press and hold the ball and roll in the direction that it DOES NOT work correctly. Continue pressing in and roll in all directions for at least a minute.
Turn the device on and see if it is working as it should. If so, you are good to go. And carry it in a case,not in your pocket.
You can also try pressing the ball in and shooting some canned air all around it.