Trackpad not functioning correctly after replacing
After replacing the trackpad, some pointing functions are not working, like dragging a window, the trackpad click sometimes does not work after restarting the Mac. In addition, after replacing the trackpad, there is a continous noice coming from the fan.
Lets run the onboard diagnostics to see if you get an error or two. Restart your system and press the D key to enter, let us know what you get.
Reference: Mac startup key combinations
Dan さんによる