Apple Hardware Test (AHT) is GONE!! after Lion install

@ Sonicray

"Also I noticed that I have an empty 200MB hidden partition in my HDD... I am guessing this was the home of the original AHT before Lion..."

The 200 MB hidden partition is used bij EFI (a sort of Master Boot Record for Apple). In the past I have accidently formatted this partition in Windows and I was not able to boot Mac OS X after that. All Apple files were gone. I had to reinstall Mac OS X completely. So be careful and do not make changes to that 200 MB hidden partition, because the partion table for Mac OS X is located there.

Please correct me if I am wrong.

I had a little time to revisit this on my original 2008 MB Air that shipped with OS X 10.5.2 and been wiped clean with SL installed then Lion upgrade on top...

Remember that the original AHT was no longer on this machine. I simply copied the AHT from the original 10.5.2 Disk 1 to the same location on the Lion installation and AHT it works as it did!!!

SO...

Copy the ".diagnostics" folder from "/System/Library/CoreServices" on your original disk supplied with your machine to the same "/System/Library/CoreServices" location on your Lion installation; and holding the D when booting again accesses the AHT:

/System/Library/CoreServices/.diagnostics

Of course it's easiest if you show your Hidden files first!

Good luck!

Wow! Excellentkimfromberwyn 🙂 2 thumbs up !

This workaround worked perfectly on my 2011 MBP that came with SL 10.6.6. I am now able to launch AHT without the DVD.

I really wonder why Apple doesn't include AHT with Lion or, at least, doesn't give access to it over internet for other types of Mac (like it does for the MBA).

Doesn't work for me.

Have a mid-2011 iMac with Lion pre-installed, no DVDs.

When I turn it off and then turn on again, immediately holding the D key on my Apple USB kbd, the startup idles for maybe 20-30 seconds before it finally shows the Apple logo and starts up normally.

So, I guess it's trying to go online and download AHT, but it somehow doesn't succeed in that. My Ethernet connection has a direct cable connection, DHCP configured, and it's also connected via Wifi to another router, with WAP2 and DHCP. Yet, it can't download the code. Weird.

Very bad idea, Apple, to rely on internet to perform a critical hardware test!

Not included in Lion, however

Apple Hardware Test can be put back in place from a back-up /TimeMachine/ or SnowLeopard install disk.

/System/Library/CoreServices/.diagnostics

Copy the ".diagnostics" folder from "/System/Library/CoreServices" on your TM or SL disk to the same "/System/Library/CoreServices" location on your Lion installation.

Holding the D when booting again accesses the AHT.

/System/Library/CoreServices/.diagnostics

Easier if you show your Hidden files first!

defaults write com.apple.finder AppleShowAllFiles TRUE ;killall Finder

defaults write com.apple.finder AppleShowAllFiles FALSE ;killall Finder

I don't understand you.

Why do you repeat something to me that you have already written once above? And it doesn't even apply to my comment since this new Mac has no SL backup and therefore there is no .diagnostics file, either.

Giving replies to people without trying to even understand what they write isn't helpful, either - it rather comes across as trolling.

If you read my original comment, you could see that I already explained in every detail that I did what you quoted to me. My message to this thread was meant to say: It doesn't always work!

And my question why someone replies to me with something that doesn't apply to my question is because his reply says clearly: "In response to <my name>". So, he did apparently try to reply to me, didn't he? That's the whole purpose of threaded commenting, if you haven't noticed.

And yes, if I wanted to resolve my own issue, I should open my own thread. That wasn't the purpose of my comment here, though.

I realize now that I should have not responded to leroydouglas' comment, though, because it appears that he did not attempt to reply to me but just used the reply button on the last entry he found. That's confusing indeed, especially if you're not using the threaded but the flat view.

Just to comment on your "Nothing to download" note. I guess that refers to my first msg saying "it's trying to go online and download AHT". Then you quote the very text from Apple that says that "These computers will start up to an Internet-based version of AHT". Well, what do you call this internet access if not downloading? The hole point of it is that the Mac will download ATH in this case, doesn't it? Please explain if I misunderstand this concept.

Good points, Sonicray. I realize now that my reply was just as unfocussed to your previous msg as the one I complained about. I should now really start a thread on "Despite what Apple Support suggest, my Mid-2011 can't load ATH over the internet". Sorry for all the confusion I caused.

Hey all, I am with mid 2010 imac and after Lion I couldn't run AHT with application DVD inserted.

Then following instructions (kimfromberwyn and leroydouglas) I have installed aht package, but still was unable to run aht. only after shutdown it worked and as I think it was running from inserted DVD.

I have MacBook Pro (15-inch, Late 2011) shipped with pre-installed Lion and Apple Hardware Test accessed by D-key.

Recently it turned out that I need to reinstall Lion. I entered using Cmd+R, created backup HDD image by means of Disk Utility and reinstalled Lion with download from the Internet. Now I have Apple Hardware Test gone!

However, when I mounted my backup HDD image with the pre-installed Lion, it turned out that there's no /Volumes/Backup Macintosh\ HD/System/Library/CoreServices/.diagnostics at all, that means that Apple Hardware Test either is not .diagnostics folder or it's located somewhere else.

Any thoughts on this?

Bug report has been filed. There's no Apple's Express Lane at Russian Federation.

Anyway, Option+D works and I can start up to an Internet-based version of AHT. I've got an idea: to capture Internet traffic and see from where a Macintosh downloads the Internet-based version of AHT.

What do you think?

I too have an Oct'11 MBP that came w/Lion preinstalled. Custom purchase in Dec'11, with a 7200 RPM 750GB HDD. Can't reboot now cause I have stuff in the pipeline that can't be quit just yet, but I can offer this to the discussion. This is the raw partition table showing all the stuff, including that which DU does not list. Lo and behold, the .diagnostics can be found by mounting the Recovery HD as follows:

$ diskutil list /dev/disk0 #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *750.2 GB disk0 1: EFI 209.7 MB disk0s1 2: Apple_HFS Macintosh HD 749.3 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3

$ diskutil mount readOnly /dev/disk0s3

$ cd /Volumes/Recovery HD/System/Library/CoreServices

$ ls -la

drwxr-xr-x 4 macjuan macjuan 136 Jun 27 2011 .

drwxr-xr-x 3 macjuan macjuan 102 Jun 27 2011 ..

drwxr-xr-x 3 macjuan macjuan 102 Jun 27 2011 .diagnostics

-rw-r--r--@ 1 macjuan macjuan 749 Jun 27 2011 Volume Name Icon

I take it, then, that AHT should pop up when I get a chance to test the D. Also, since the 10.7.3 update is supposed to update the Recovery Partition too 😮 hope I don't lose the AHT when I bite the bullet!

Hi folks,

I have 2010/08 MBP and i tried, like you, to launch the AHT while pressing D, nothing, so i tried ALT & D and it begun to load, i guess with internet access, but after few minutes it says that my laptop is not in the list for AHT.

No success while trying to boot on the second DVD.

See u

I have a brand new iMac that came with Lion 10.7.3 and as others have mentioned there is no AHT on the computer and thus starting holding done the D does not work. I was lucky that someone in this post said they used alt-d and that did work. It loaded from the internet and ran. Seems to me that Apple should make AHT available for download. This moving everything to the internet/cloud is going to cause problem for a lot of people who have dial up or maybe no internet at all. I feel sorry for them. Also my new iMac came with no DVDs, manuals or booklets. I still like having them and feel Apple is going in the wrong direction. Seems you need to buy Applecare just so you can ask questions and find out how to run AHT and other tools.