Originally Posted by gjjh
I was surprised that this fixed a stuck trackball in ten seconds after an hour of messing with it.
Fold a paper towel several times and soak a small area in rubbing alcohol.
Hold the blackberry facing downward with this moist area of the towel between your finger and the trackball.
Rub the trackball in a circular motion until you feel the trackball running in all directions smoothly.
With the Blackberry facing down, only a film of alcohol is carried to the "gunky" rollers by the trackball.
This worked for me! (With a Blackberry Curve 8320 whose problem was the track ball had stopped being able to cursor down.)