I ran into problems with my Trackball on my Blackberry Curve 8310 so did a search to see if I could get it going again. The ball scrolled up, left and right only. Major pain in the butt! But managed to get it going by cleaning the rollers. I will be searching for a replacement now that I know how to replace this trackball. It will take much less time. I don’t think I will ever attempt cleaning it again.I just did this and it took me 2+ hrs. I don’t have steady hands and good eyesight either.This is a good link with helpful cleaning info blackberryforums.com.. I would recommend REPLACING the trackball rather than cleaning it. I found this Video Clip on YouTube below will show you how to change it.