Your Mac Has A Hidden Diagnostic Menu - Here's How To Enable It - bgr.com
If you have an Apple Silicon Mac, press and hold the power button, and continue to hold it even after your computer turns on and you see the different startup options. Finally, press and hold Command + D on your keyboard for the Mac to restart. On an Intel Mac, on the other hand, you immediately need to press and hold the D key on the keyboard as the Mac starts up.
Apple has a hidden diagnostic menu that can come in handy whenever there's something faulty in your computer or if you're planning to buy a Mac that has been owned by someone else before. While some of the most common MacBook problems can be solved fairly easily, there are a few others, especially related to the hardware, that require a more careful look, and you can be the first to look at them. Apple's Diagnostics tool can determine which component of your computer might be at fault, and you can check it on both Apple Silicon and Intel-based Macs.
While BGR doesn't recommend anyone buy Intel-powered Macs, as Apple is finally killing software support for them with macOS Golden Gate, if you're on the verge of buying a new computer but you don't want to pay the recent extra price of the M5 Macs due to the memory crisis, making sure the Mac you want to buy is in good condition is a smart choice. Besides, if you're selling your Mac to someone, showing that everything is fine can be another important selling point to ensure peace of mind for you and the person getting your computer.
Before running Apple's Diagnostics tool, the company recommends that users ensure they have the latest macOS update. Even if your computer has run out of updates for a while, it's always good to check if you're running the most stable version of macOS for your machine. Once you do that, shut down your Mac and disconnect all possible external devices from it, besides the keyboard, mouse, display, Ethernet connection, and its power cord.
If you have an Apple Silicon Mac, press and hold the power button, and continue to hold it even after your computer turns on and you see the different startup options. When you see Options, you can release the power button. Finally, press and hold Command + D on your keyboard for the Mac to restart. On an Intel Mac, on the other hand, you immediately need to press and hold the D key on the keyboard as the Mac starts up. If the key doesn't work, then you need to press and hold Option + D at startup. When a progress bar appears, or you're asked to choose a language, you can release the key(s).
Follow the instructions on the display, make sure you're connected to the internet and that you're running macOS 26 Tahoe or later. You can then choose what kind of diagnostic you want to run, such as about the display, keyboard, trackpad, and more.
After you run the diagnostic, Apple will show a reference code. The one you're looking for is ADP000, which means no issues were found. The company has a support page with around 100 possible issues, ranging from the ambient light sensor to onboard memory or the Antenna Connector Board. Depending on the matter, Apple will offer you the possibility to troubleshoot yourself, such as if it doesn't detect the MacBook is not charging but you also didn't put it to charge, or something more serious that requires you to contact Apple or take the computer to a repair shop.
Customers can also go to independent repair providers or have Apple send genuine parts, tools, and more, since the company has its own Self Service Repair page. That said, whatever you need to ensure the Mac is good, the first thing you should do is run Apple Diagnostics, and from there, understand if everything is alright or if you need to talk to an Apple representative, try to fix it yourself, or take it to a repair shop.