• Apple Diagnostics is a diagnostic tool for your computer's internal hardware, including the logic board, memory, and wireless components. Even if your Mac doesn't start using macOS, you might be able to start it with Apple Diagnostics.
• Follow the instructions in the Apple Support page to utilise Apple Diagnostics. To test your Mac, use Apple Diagnostics.
• Before you begin, you might wish to print the instructions. Select File > Print from the File menu, then click Print.
• Contact Apple Support or take your Mac to an Apple Store or an Apple Authorized Service Provider if Apple Diagnostics detects that your Wi-Fi card isn't working properly.
• External hardware components, such as a USB device, and non-Apple devices, such as PCI cards from other vendors, are not checked by Apple Diagnostics. It doesn't look for problems with macOS or software, such as app or extension conflicts.

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