Sometimes the trackball gets stuck and won't move in a certain
direction. When I take the trackball out, I don't see any dirt or any
other obstruction. What could be causing the trackball from rotating in
a direction (usually downward). Thanks for any advice/suggestions.
The ball fell out of mine once and put a crease in it...
examine it for creases on the ball itself.
Check the roller bearings too. It may help to cover up the
optical window and spray silicone liberally into the ball
cavity so it seeps into the bearings' bushings. This will
reduce wear even if they still rotate.
That's about all there is to it, if the ball is "perfectly"
round still and the bearings rotate freely it shouldn't get
stuck. If there is a crease in the ball there's probably
nothing you can do to completely fix it, but you might be
able to take a hard curved object (like the back of a
spoon?) and "even-out" any creases some, at least enough
that the ball movement just feels off instead of hanging up.
IMO, they're not too expensive so if you need it 100% and
the above doesn't help, just buy a new one.