GoKawiilApple Diagnostics tool helps isolate MacBook hardware faults during startup
Apple offers a built-in tool called Apple Diagnostics that tests a MacBook's internal hardware to determine whether issues like shutdowns, display glitches or keyboard failures stem from hardware or software. The tool isn't found in System Settings but is accessed during the startup sequence, and the steps differ depending on whether the machine uses Apple silicon or an Intel chip. On macOS 26 Tahoe and later, users can run individual tests on components like the display, keyboard or trackpad, while older systems run the full diagnostic automatically.