Originally Posted by ss1248
My Curve had the same issue too (after a day of skiing - I'm an idiot.) In addition to the trackball not clicking, holding down alt or shift for a number/capital letter wouldn't work, and typing in general was slower (key presses were missed.)
I fixed it by removing the trackball, removing the copper colored piece on the circuit board that the "spoon" makes contact with, and then cleaning the contact underneath of that with a pencil eraser. I didn't see any, but there must have been a bit of corrosion there as now all of the functions work again! (I'm not sure how the keyboard ties into the trackball, but in this issue it does.) To reassemble, stick the copper piece back on (like a sticker) and reassemble the trackball and trim ring.
Pulling off the copper piece takes a bit of work, but go at a corner very carefully with an x-acto knife (or something very thin/blade-like) and slide underneath of it, and then use tweezers to remove it the rest of the way. (It's like a sticker.) Be careful not to cut the copper piece or lose it once it's out of the phone as replacements aren't available, so you'd have to find another BB to swap a new one from if yours is lost.
This is the correct procedure to follow if your trackball click function is lost. I have performed it quite a few times on multiple berry's and have had success every time. What happens sometimes is moisture can get into the contact's housing which causes some corrosion. By prying up the tape slightly exposing the contact, you can clean the corrosion with a small blade. What I have had the most trouble with is with the resetting of the contact into the housing. It can take multiple tries to get the contact to sit it the perfect position so that the edges make contact with the side contacts and the center of the button is able to touch the center contact upon depression. Be very careful when cleaning the contact itself with alcohol because if you do not allow enough time for the alcohol to dry, your contact will again become corroded and not function correctly. I would love to post a step by step instruction on this procedure but I do not have a high resolution camera to take pictures.
EDIT: I have found a nice guide by member CrackBerryHead that details the procedure: http://www.audsound.net/_share/bbtb_select_fix.pdf