Apple Diagnostics helps identify hardware problems on MacBooks, whether your Mac keeps shutting down or has display issues. First, check your MacBook model by selecting About This Mac from the Apple menu to determine if it uses Apple silicon or Intel processors. Before running diagnostics, install available macOS updates, disconnect external devices, and ensure good ventilation.

For Apple silicon MacBooks, press and hold the power button until the startup options screen appears, then press Command (⌘) and D to enter diagnostics. Intel MacBooks require turning on the computer and immediately pressing and holding D, or Option (⌥) and D if the first method fails. The diagnostic experience varies by macOS version; macOS 26 Tahoe or later allows individual hardware testing, while earlier versions run tests automatically.

Apple Diagnostics can identify faults in internal components like memory, batteries, and displays, but cannot test external hardware or software issues. A clean test returns ADP000 code, meaning no hardware issues were detected, though software or external accessory problems may still exist.