Note:

Trackpad not working? It can be difficult to diagnose the exact problem. Is it the cable? The trackpad itself? Something not aligned correctly? Any of these could be the issue.

• Question 1. : Not possible to click ? Answer : Try to reset the SMC (System Management Controller) in this way:

1. Attach the MagSafe power cord
2. Power off the MacBook Pro
3. Press the L-Shift/Control/Option and Power button at the same time and hold.
4. Release them all at the same time
5. Then power on the MacBook Pro

• Question 2. : Click works fine but the trackpad doesn't detect fingers the way it used to ? Answer : You probably need to slightly loosen the screw in that little triangle shaped groove by the bottom center of the trackpad. That will lessen restriction on the pressure sensor's range of movement so that it can detect slight touches.
• Question 3. : After installing the new trackpad ,couldn't click, as the clickable area of the trackpad wouldn’t move at all ? Answer : To fix this,u should very slightly and gently pry the two small “pods” (on the long side opposite the connector) upwards (ie) towards the tactile surface.Once mounted again, it will work perfectly well.
• Question 4. : The trackpad works intermittently or only in some areas, or will track but won’t click ? Answer : Symptom of a swelling battery will be,it requires replacing the battery and will be no issues.