Your Mac includes a built-in tool called Apple Diagnostics (formerly called Apple Hardware Test). This tool will be handy if you are dealing with a hardware issue and not a software issue. You can use it to find and diagnose issues with your Mac’s internal hardware such as the Wi-Fi hardware, the Bluetooth hardware, Touch ID, the fan, or the power adapter, etc.

Prepare your Mac

• If you can install the latest macOS updates (https://support.apple.com/en-us/108382)
• Disconnect all external devices except keyboard, mouse, display, Ethernet connection and connection to AC power
• Determine if you have an Apple silicon Mac or an Intel Mac, go to the  Apple menu > About This Mac to find out (on a Mac with Apple silicon, About This Mac shows an item labeled Chip, followed by the name of the chip, on an Intel-based Mac, About This Mac shows an item labeled Processor, followed by the name of an Intel processor)
• Shut down your Mac (if you can't shut it down normally, press and hold its power button for up to 10 seconds, until your Mac turns off - every Mac has a power button; on laptop computers that have Touch ID, press and hold the Touch ID button)
• Turn off your Mac, then wait a few seconds for your Mac to completely turn off

On an Apple silicon Mac

• Press and hold the power button on your Mac (on laptop computers that have Touch ID, press and hold Touch ID)

• As you continue to hold the power button, your Mac turns on and loads startup options

• When you see Options, release the power button

• Press and hold Command (⌘)-D on your keyboard until your Mac restarts

On an Intel Mac

• Turn on your Mac, then immediately press and hold the D key on your keyboard as your Mac starts up (if using the D key doesn't work, press and hold Option (⌥)-D at startup instead)

• Release the key when you see a progress bar or you're asked to choose a language

Run Apple Diagnostics

Follow the onscreen instructions, which vary based on your Mac, the version of macOS that it’s using, and whether certain parts of your Mac have been repaired or replaced.

As you follow the onscreen instructions:

• If your Mac isn’t already connected to the internet, you’re asked to choose a Wi-Fi network, or you can use an Ethernet cable to connect to your network

• If asked to review terms and conditions, you might be given the option to run diagnostics offline (in that case, click Run Offline)

• In macOS Tahoe 26 and later, you’re asked to choose a specific diagnostic to run, such as a diagnostic for your built-in display, keyboard, or trackpad; in earlier versions of macOS, this is automatic

When testing is complete, Apple Diagnostics shows the results. If you see one or more reference codes and need more explanation, refer to the list of Apple Diagnostics reference codes (https://support.apple.com/en-us/102334).

If you can't use this information to resolve the issue on your own, you might need service (https://getsupport.apple.com/?caller=kbase). Provide the reference code you receive from the test when taking your Mac to an Apple Authorized Service Provider, Apple Store, or an Independent Repair Provider. Genuine Apple parts are also available for out-of-warranty repairs through Self Service Repair (https://support.apple.com/self-service-repair).