How to Use Apple Diagnostics on an Intel Mac Press the power button to turn on your Mac, then immediately press and hold the D key on your keyboard as your Mac starts up.

If you click Get Started for more information about an issue that Apple Diagnostics has identified, your Mac will boot into macOS Recovery Mode and display a web page asking you to choose your ...

Apple Diagnostics is designed to put your hardware through a variety of tests designed to detect power supply, battery, graphics, logic board, USB and a huge range of other potential problems ...