Trackpad Is Completely Unresponsive
If your trackpad is entirely dead, don’t despair—it could also be a simple settings issue.
The way to test this is to check for a physical mouse connected to your system, either via USB or Bluetooth. If you do, try disconnecting it. Does your trackpad now work?
In that case, your system has been set up to ignore trackpad input when it detects a mouse.
As long as you’re running OS X 10.7 Mountain Lion or later, you can change this setting by going to
System Preferences > Accessibility > Mouse & Trackpad and unticking the checkbox next to Ignore built-in trackpad when mouse or wireless trackpad is present.
It’s also possible that your Mac thinks another peripheral accessory is a mouse. Trying disconnecting everything (keyboards, printers, gaming controllers, and so on) from all your machine’s ports and see if it makes a difference.