Trackball maintenance is easiest on BlackBerry Pearls, Curves and 88xx models, since the trackball and its housing can be removed without opening the phone. The trackball and housing is the same for these three models, so you can interchange them if you need to. Note that RIM doesn’t support doing this yourself, so if you are worried about your warranty status, take your BlackBerry in for service instead of trying to repair it yourself.
Take a small flathead screwdriver and place it between the silver ring around the trackball and the BlackBerry key. If you don’t have a screwdriver, any small, flat object will do. Push out on the screwdriver to pop that side of the trackball housing out of place. Now place your screwdriver on the other side of the silver ring and do that same thing. You can now pull the housing and the trackball out of the phone.
If you are just cleaning the trackball and control board, and not replacing the trackball, you need to be careful when you remove the housing since you can break the tongs that lock it into place. Pull the housing as straight up as possible, since pulling it up by one side can snap the tongs on the other. If you do break the housing, you may need to replace it in order for it to lock back into the BlackBerry.
Use a small brush or a dry cloth to clean off the trackball and the contacts that you can now see inside the hole where the trackball goes. For the best cleaning results, use a small brush and isopropyl alcohol (It needs to be at least 95% alcohol, preferably 98% or higher) to clean the circuit board.
Place the trackball back in the cavity, use the new trackball if you are replacing a bad one. Position it so that the four plastic tabs are pointing to the right and left. It will slide right in. Place the plastic housing over the trackball, the tongs should be located to the left, bottom and right. Push down on the housing to snap it in place.
If you cleaned the trackball and it is still not working, replacing the trackball is the next step. If you replaced the trackball and it is still not working, the phone will probably need to be replaced.