Highly recommend adjusting the T6 torx screw to ensure correct operation of the trackpad. Have the battery connected but not installed (so as to have access to the screw). Start up the computer. Test the click function at any time. Using very minor adjustments, turn the screw until you can see that the computer responds to clicks. When you are satisfied that it is working correctly, go ahead and shut down the computer and proceed with reassembly. It doesn’t hurt to give the unit a good clean while you are in there as this will avoid problems later, eg overheating due to dust blocking airflow etc. use an artists paintbrush and a vacuum cleaner or (gently) blow it away with (clean) compressed air. Some compressors have oil spray or water from condensation in the air, so use a filter in the line to avoid contamination.