Apple Diagnostics Test
Regulo Akers
I tried to run Apple Diagnostic by pressing and holding "D" immediatly after running computer as apple documentation says but when I do this I get network selection screen (I didn't press "option" + "D"). But after selecting the network I don't see any diagnostic started. Just the same network selection screen where I can reselect the network. The same goes if I tried to press and hold "option" + "D".
Apple computers ship with a pre-installed suite of hardware diagnostic tools, known as Apple Hardware Test (AHT). In principle you can start them by holding the d key while booting. Newer models support holding option d to load AHT over the internet. Refer to the official Apple documentation for details: Using AHT on Intel-based Macs, Mountain Lion, Mavericks and Yosemite. Apple redesigned the AHT, now called Apple Diagnostics, for Macs introduced after June 2013. Consult the reference codes to interpret the results.
If however, you reinstalled an older computer from scratch, the diagnostic tools might no longer be available. Unless you have the original disks that came with your computer, there seems to be no way to restore the AHT.
It happens that Apple provides disk images with AHT for most computers, but does not make the links publicly available. Various blogs and forums, mostly Riven by Five and MacForum.ro have gathered a list of download links. The rest were obtained by scraping _Hardware_Test/ for all the links of the form 0(1822)-\d4-A.dmg.
Download the AHT for your computer model and use the contents to restore the /System/Library/CoreServices/.diagnostics folder, then reboot while holding d to start the diagnostic tools. Alternatively you may try with a bootable USB stick, as described below. This is also the preferred way on OS X 10.11 or later, where the System Integrity Protection (SIP) no longer allows writing to system folders.
When trying to open an old dmg you may get the error 'legacy image should be converted'. To convert it to a newer format, open Disk Utility, in the menu Images click on Convert and select the dmg to convert and save it under a new name.
Note that there is no one-to-one correspondence between hardware model and AHT. For some models no hardware test could be found, while others seem to have multiple AHT. As the differences are not clear, feel free to try them out, to see which one works best for your hardware.
Yes, I use wireless keyboard but it's connected to my iMac by USB. I don't think that's the problem because keys on my keyboard work while booting (I can open recovery mode). I don't know why I'm getting network selection screen instead of apple diagnostic screen.
Sorry. I posted question from another computer. I'm working on iMac 2020 with Intel processor and Mac OS Ventura 13.3.1. So I don't have AHT. Can reinstalling Mac OS and "erasing all content" (from settings) delete diagnostic folder?
Did reinstalling Mac OS and "erasing all content" in settings delete diagnostic folder (/System/Library/CoreServices/.diagnostics)? Is location of diagnostic folder is the same (/System/Library/CoreServices/.diagnostics)?
Hi, can anyone help verify this, or suggest a fix? Since updating to 11.3 today, I cannot use Apple Diagnostics by holding D on startup. I get into Diagnostics, select my language, but then it is just a black screen with no testing taking place. It work previously on 11.2.
To get started, what exact model of Mac are you using, and what issue are you troubleshooting that requires using diagnostics? This can be helpful in case you may have a hardware issue preventing the use of diagnostics to begin with.
Howdy, this is affecting a 16" Macbook pro and a 2019 Macbook air. Diagnostics test runs fine on a mac with 11.2, but as soon as we upgraded to 11.3, Diagnostics doesn't run. You can boot into it, select language, then blank screen, not the usual test.
Well the problem occurs with the online or offline version. Of course I've got an active internet connection. As per first post I know how to use diagnostics, I'm just reporting that I'm finding an issue with it after upgrading to MacOS 11.3, and on the same machines it wasn't an issue on 11.2 previously.
I've since installed a new SSD and aftermarket RAM. The computer appears to be functioning normally (I'm typing this post on it), but I'd like to run the full hardware test to verify everything is OK.
But I can't seem to get it to load into the hardware test. I've tried holding down D before pressing the power button on as well as right before the grey screen comes up. I'm confused because I've done this before without any problems.
Same thing here (similar model MBP, same mods). Learned that Option+D does the trick. However, if you get what I see, the AHT fires up and then says that it doesn't support this model of machine. No funny business, it's an Apple MBP (no hackintosh here), but I added a OCZ Vertex 3 and I've tried pre-8GB RAM kit (stock) and post, no difference.
Additional Information
Apple Hardware Test is included on the DVDs that are shipped with some Macintosh computers. If the copy on your hard drive becomes unavailable, use the DVDs to run Apple Hardware Test.
Had the same problem listed here on my iMac Pro, and it turns out that if you have a firmware password set, then the hardware diagnostics system won't work at all, and there is no indication of this, but a nice fellow named Felix from Apple was able to suss that out with me.
To disable firmware password or check its status, you need to restart the system while holding down Cmd+R. Note: If a firmware password is set, a screen will show and ask you to input the password. Once you do that, you're greeted with various options like Disk Utility or Install macOS. Ignore them and follow the instructions below:
The Apple KB article is inaccurate. After many unsuccessful attempts to launch the Apple Hardware Test on my MacBook Pro Early 2011 15",I discovered you need to hold Command + D during startup, not just D.
I ran into similar situation with my mid 2011 mac-mini (with non mac keyboard/mouse & aftermarket updated RAM). After pressing 'D' at startup it searches for internet, eventually asking to select wi-fi connection (no available connections displayed though). There's an option to specify wi-fi access point name & password but for me after putting the credentials the wait icon just kept revolving.Thankfully, I got it working using the ethernet cable.
I've had a similar problem whilst trying to run tests on a second hand Mac mini (Late 2014). I tried holding D, alt-D, cmd-D, cmd-R, alt-cmd-R, and two different wired keyboards, but each time the machine would just boot to the normal login screen.
Perhaps here, the SMC was holding onto network information from the previous owner and getting thrown by the different network environment in my house until it was reset. Disappointing there were no error messages if that is the case.
Mid 2012 MBP here. Just bought it and wanted to run AHT. Tried D, CMD D and OPT D, all bring same thing: "Internet Recovery". I have ethernet cable plugged in but it ignores that and wants wifi password (grr). I enter wifi password, then it connects but bugs out with black screen error:
Apple Diagnostics is a built-in test that helps determine which hardware components are causing the problem and pinpoint system failures. The test checks the RAM, power controller, logic board, battery, and other wireless modules.
A great feature of Apple Diagnostics is that after it checks your hardware, it displays an error code and provides you with clear solutions and assistance from Apple Support. You can write down the error codes (known as reference codes) and either do the research yourself or contact Apple.
When referring to a Mac diagnostic test, you may also hear about Apple Hardware Test (AHT). This is a predecessor of Apple Diagnostics (AD), and they have some minor differences. Mainly, the results of AHT aren't conclusive and descriptive. AHT is used in Macs released in 2012 or earlier, while AD is a more advanced analog that works with newer Macs.
Sometimes you search for how to diagnose your Mac after you have already experienced certain problems with the system. This is similar to many people who only go to the doctor when something starts hurting badly. It is always better to get regular checkups and prevent health problems, and the same goes for computers. It is advisable to monitor and clean your Mac on a regular basis, and apps like CleanMyMac X are incredibly helpful.
Many so-called junk files tend to accumulate on your computer, and cleaning them manually either takes a lot of time or requires special knowledge to discover their location. With CleanMyMac X, you can perform regular cleanups with just a few clicks. It is also possible to search for specific types of files if you want to get rid of something particular.
Another app you might find useful in this situation is iStat Menus. It helps with monitoring various stats and providing feedback on the performance of your Mac. You will get info about the memory, temperatures of different parts of your computer, disk performance, and more.
You can display all this data in different kinds of charts for easier comprehension. It is also possible to turn on the specific features you need, which you will see in the menu bar. With all these stats at your disposal, you can always monitor the performance of your device easily and take action anytime certain issues occur.
After performing Mac hardware diagnostics, you'll get the list of found issues with detailed descriptions and related reference codes. Each code stands for a particular error and helps you quickly figure out the next steps. Usually, an error description will suggest possible solutions. However, to fix a specific problem, Apple Diagnostics might recommend you contact Apple or take your Mac to an Apple Authorized Service Provider or Apple Store.
Sometimes, there are no issues with your hardware even when the computer seems to have performance issues. In this scenario, the problem might be in your software. The storage might be full, tons of unnecessary and broken files might clutter the system, etc. In this case, we recommend you do a cleanup scan with the help of CleanMyMac X.
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