How to Use Apple’s Hardware Diagnostics to Find and Fix Mac Glitches

Is your Mac acting up? It may be more than just a dodgy software update; sometimes it could be as serious as a hardware failure. Therefore, you need to know how to use Apple’s Hardware diagnostic tools to find and fix what’s wrong. Before we start, if you are at all unsure of what you are doing, stop and take your Mac to an expert.

There are a couple of ways to do this and which way depends on your Model and OS X version. To find that out, click on Apple Menu>About This Mac:

• If your Mac is 2013 or newer, you will use Apple Diagnostics, built-in to the Mac
• If your Mac is 2012 or older and on OS X 108.4 or later, you will use Apple Hardware Test, built into the Mac. If the OS X is earlier than this, you need to use the USB flash or software disc that came with the Mac

Apple Diagnostics

1. Disconnect any external device with the exception of the keyboard, speakers, mouse, and display
2. Click on Apple Menu>Restart
3. As the Mac reboots press the D and hold it
4. Diagnostics will start and will list all problems found, with an Apple support reference code
5. Write the results down and then check on Google to find out what the problem is and the fix for it

Apple Hardware Test

1. As above, disconnect all but the keyboard, mouse, speakers, and display
2. Click Apple Menu>Restart
3. As the mac reboots, press D and hold it
4. On the Apple Hardware test screen, choose your language and press Return
5. Run the tests and write down the results, checking them on Google to see what the problem is

Using Your USB Flash Drive or System Software Disc

Only use these if your Mac was supplied with them – do not attempt to use any that came with a different Mac model because they won’t work.

1. Disconnect everything except for the display, mouse, keyboard, and speakers
2. Put the USB flash or system dis into your Mac
3. Click on Apple Menu>Restart
4. As the Mac reboots, hold the D key down
5. Chose the language you want to use and then hit the Return key
6. Follow the instructions on the screen to run the tests
7. If any issues are detected, you will see an alert message; write down what it is along with any reference codes
8. Check them on Google to see if you need to call Support or not

Neither Apple Hardware Test nor Apple Diagnostics will check any of the external hardware, like non-Apple devices, Firewire, USB, etc. they also do not check the operating systems or any problems that may be related to software i.e. extension or app conflicts.

If no issue is detected but there is definitely a problem, you may need to reinstall your operating system.