Macs from Apple are quite decent in their quality and don't run with issues frequently. In case it does, then what should you do? I hope we all are qualified enough to fix the software issues, but when it comes to hardware, Apple is our only savior. Regarding it, we can, at least, find the root cause of the issue by running the Apple Diagnostics on our Mac.
Today we will introduce you with Apple Diagnostics, how to use it, its error codes, and almost all the things related to it. So, just read below for complete details.
What is Apple Diagnostics?
Apple Diagnostics is a hardware test, which when conducted, checks all the hardware connected to the Mac. The test usually takes a long time, and also, it needs you to be connected to the internet. Before going forward with using it, make sure you detach all the extra hardware connected to your Mac. Only connect Keyboard, Mouse and Ethernet (if any).
How to use Apple Diagnostics to Identify Mac Issues
To enter the Apple Diagnostics, shut down your Mac. Now start your Mac and immediately press and hold the “D” key on your Mac Keyboard. Keep it holding until you see Apple Diagnostics screen. The test will begin from here after you get online, which will take few minutes to complete. After the test is completed, you'll be presented with the test report.
Using the Apple Diagnostics report
Once the test is conducted successfully, you'll have a report being shown on your Mac screen. You can send this report to Apple by using the “Get Started” link. Doing this will open the Mac OS X Recovery Mode and Safari will open the Apple's support pages. From here, you can send the report to Apple and check for the relevant information.
Understanding the Apple Diagnostics codes
There isn't much you can do about the problem, but what you can do is that you can, at least, get an idea of who the culprit is. Every hardware has its code, and the report shows the error with code. So below is the meaning of codes that might be displayed.
Please note, there are plenty of codes and it's not possible to list each of them here. We have listed the codes related to hardware, which is relevant to regular users. In case you are looking for a complete list, try having a look at Apple Diagnostics Reference Codes.
CNW001-CNW006: Problems related to Wi-Fi
CNW007-CNW008: Wi-Fi hardware has been detected
NDD001: Hardware issues related to USB devices.
NDL001: Indicates problems related to Bluetooth hardware.
PFR001: Mac firmware issue.
PPF001-PPF004: Fan issue.
PPR001: Processor issues
VFD001-VFD005: This is the one that is experienced by most of the Mac users; it means “Display issues” have been detected.
VFD006: Issue of Graphics processor
VFD007: Display problem
VDH005: Unable to launch OS X Recovery
If any of the above error comes to your screen, then it's the time to book an appointment with Apple and resolve the issue. Don't try to repair it on your own; you might get few more errors trying to fix just one.
Now, if you get ADP000 as a code, then it's time to dance. That's because it means the test resulted is no issue. Everything on your Mac is working perfectly fine.