How to Run Diagnostics on Mac to Fix Hardware Problems [Updated]

A majority of Mac owners are likely to have a good experience using Mac for months and even years. Nonetheless, every so often, a problem in the hardware might amplify that would substantially affect the performance of your Mac. Then you might end up with having a Mac repair that might cost you a lot. Actually you don't need to do that. Finding out the fix of the issue – no matter in software or hardware – is the key step towards repairing them. In this article you will find out how to run diagnostics on Mac. Keep on reading!

What Is Apple Diagnostics or Apple Hardware Test on Mac?

Apple has developed their MacBook and other Mac devices to be exceptionally reliable. There is a possibility that you might never experience an issue related to the Mac hardware with your device, however, even the best designs sometimes have the probability to break down. Thankfully, the machine has MacBook Diagnostics built into it to help overcome hardware issues like these.

Which account of Mac hardware test you should run varies from the Macs released in different years. For instance, Macs launched prior to June 2013 will run Apple Hardware Test. On the other hand, systems that were released after June 2013 will run the Apple Diagnostics Test.

As to what these actually are, let me tell you that the Apple Hardware Test should interest the owners of older Macs more, in order to determine the problems occurring in their machines. As it was the basis of Apple Diagnostics, these are pretty much identical when being operated.

apple diagnostics

What Are the Common Hardware Problems on Your Mac?

Apple Diagnostics is intended to get your hardware through a range of assessments developed to sense battery, power supply, logic board, graphics, USB and a multitude of other possible shortcomings. Whilst this assessment does not cater to each and every occurrences, it is right to find out the most usual hardware issues that you can experience whilst you use a Mac.

Following is the list of most common hardware issues and their Apple diagnostics codes in Mac, then you can figure out what are the problems with your Mac and fix it accordingly.

  • CNW001-CNW006: Wi-Fi hardware glitches (or CNW007-CNW008), which shows now Wi-Fi hardware has been spotted, which might also be an issue if your suppose you have a similar hardware).
  • NDD001: USB hardware issues (NDL001 indicates Bluetooth hardware problems).
  • PFR001: Mac firmware problem.
  • PPF001-PPF004: Fan problem.
  • PPR001: Processor problem.
  • VFD001-VFD005: This is the one that I have seen most often, it means “Display issues” have been identified.
  • VFD006: Graphics processor problem.
  • VFD007: Display issues.
  • VDH005: Cannot launch OS X Recovery.

How to Run Apple Diagnostics on Mac

When running MacBook diagnostics, you are suggested to switch off all peripherals except for your monitor, mouse, keyboard and Ethernet (if connected). You are also suggested to ensure that you have the label and code of your Wi-Fi connected in case this is the option you choose to access the Internet. Below is the full guide on how to run diagnostics on Mac:

  1. Select Apple Menu on your Mac, then restart it, click and hold the D button while your Mac restarts.
  2. Keep holding the key until a list with a different code displays on the screen.
  3. Choose a language and that will automatically launch the Apple diagnostic tool.
  4. When the test completed, it displays a list of the hardware issues that have been identified.
  5. Follow the on-screen instructions being given on the screen.
  6. In order to put your Mac from the built-in recovery disk, turn on the webpage namely, Contact Apply Support in a browser and hit “Get Started”.
  7. In case Mac hardware diagnostics identifies that your Wi-Fi card is not operating aptly, reach out to Apple Support or bring your machine to an Apple Store of any other Authorized Service Provider for Apple.
  8. To change the language again, click on Command-L.

run apple diagnostics

How to Run Apple Hardware Test on Mac

Available for Macs were Released Before June 2013

Users of older Macs will run the Apple hardware test to find out the problems with their Mac’s hardware, as it was the basis for Apple Diagnostics. Follow is the given instructions to run it on your device:

Noted: Make sure that your Mac is on a stable, hard and flat surface that supports ventilation.

  1. Detach all the external devices connected with your Mac except for your display, mouse, keyboard and Ethernet link. In case you are not able to disconnect all the devices, an error message may pop up when you run the Apple hardware test.
  2. Now turn off your Mac and then restart it, click and hold the D button till an Apple Hardware Test icon displays on the screen.
  3. Choose your language and hit the right arrow of click on Return.
  4. Click the Test button or press T to begin the test.
  5. Check the test results in the lower-right section of the screen.
  6. Click Restart or Shut Down to end the test.

run apple hardware test

Once you successfully run these two tools, you would be able to see the results generated by your diagnostics by verifying the codes generated with the detected problem statement. The fortunate thing is that problems of hardware do not occur much and a majority of such problems can be fixed. Nonetheless, most of these issues require expert repair by any Apple Professional or Service provider. Do not forget to keep a backup of your Mac data before you go forward to fix the hardware issues with an expert.

How to Get A Younger, Faster and Healthier Mac in The Future

These hardware issues have the potential to make your Mac very slow and often leads to more severe, big issues. Thus, time is of essence for detecting any hardware issues. Actually, you can prevent such problems from happening in future, just by running a regular maintenance on your Mac and optimizing it. Cleaning your device takes another whole process that requires much time and efforts. Hence, if you would not mind an application that clean up your Mac and optimizes it for future, the Umate Mac Cleaner is the right option for you!

How to Get a Younger Mac with Umate Mac Cleaner

This application can be used to slim down your hard drive and make it lighter and even healthier. It comes with a long list of useful features that can clean up your device. Some main features offered in the Umate Mac Cleaner are:

  • Clean up all junk folders and files that may exist on your hard drive.
  • Delete large and duplicate files on your Mac.
  • Erase your personal information on Mac to protect your privacy.
  • Uninstall unwanted applications and eliminate extensions.

How to Get A Fast Mac with Umate Mac Cleaner

Umate Mac Cleaner has another amazing feature called “Speed Up Your Mac”, which gives you 4 options to boost the performance of your Mac devices: disable the startup items, deacivate the heavy consumers, remove the launch agents and free up RAM. After performing these features of Umate Mac Cleaner, your Mac will run much faster and get greater performance than before.

All the features of Umate Mac Cleaner can be performed with simple clicks. And it really works! You can get many benifits by using this app.

  • It is supported to clean up 40+ junk files. (More cleanable junk files compared to other competitors)
  • It can free up lots of  storage space for your Mac. (4X free space than before)
  •  It can make your Mac run faster and improve its performance. (2X greater performance than before)

Then, here is the question: how to use Umate Mac Cleaner? The app is super easy to use with intuitive user interface. Just follow the below steps to clean up and optimize your device.

Step 1.Install and launch Umate Mac Cleaner on your Mac. (It is compatible with For macOS 10.15 Catalina - 10.9 Mavericks)

Mac version

Step 2.Select a feature that you need and scan for your Mac system. (Clean Up Junk/Delete Large Files/Delete Duplicate Files/Erase Private Data/Speed Up Mac/Manage Apps & Extensions)

umate clean up junk

Step 3.Clean Up and optimize your Mac by following the on-screen instructions.

umate deep clean

Closing Words

We wish that you never require to run diagnostics on Mac and use these hardware repairing tools, but there is no loss in knowing the right tools and applications to make your system healthier and better performing. And we recommend Umate Mac Cleaner. It can be a great cleaning tool for your Mac and make it much healthier.