If you suspect that the hardware in your Apple Macintosh computer has become faulty. By using a tool built into macOS called Apple Diagnostics, you can check the internal components in your computer to see what might be causing a problem or find system failures.
A diagnostic test will take roughly 2 to 5 minutes and will check the RAM, power controller, logic board, battery and wireless modules on your computer. If an error is found you will be presented with a reference code, that you can research yourself, or present to an Apple certified engineer.
Note: The method shown in this video for accessing Apple Diagnostics, is for any Apple Macintosh computers running Apple Silicon hardware. If you have an Apple Macintosh computer running on Intel hardware the method for accessing Diagnostic mode is different.
Quick reference notes:
- To place your Apple Macintosh computer into Diagnostic mode, first power down your computer.
- Now with our computer shut down if we press and hold down the power button for roughly 20 seconds or until our display shows us the Start-up Options screen.
- From within the Start-up Options screen, we need to press and hold down the Command and D keys on our keyboard.
- We can release our fingers from the Command and D keys, when our computer reboots and we are shown the Diagnostic mode.
- After choosing a language, we can choose to either run a diagnostic test offline, or by selecting I agree run a diagnostic test that will send data to Apple.
Notes: Running a diagnostic test will take roughly 3 to 5 minutes to complete. If you are testing a laptop you should connect your computer to the mains while you run your test.
Apple article – Use Apple Diagnostics to test your Mac