How do I use Apple Hardware Test on mid-2010 21" iMac running El Capitan

Well, I guess the question topic says it all! Either I've forgotten how to do it, or it no longer works the same...


Anyone know?


Thanks!

iMac, OS X El Capitan (10.11.1), Mid-2010, 12GB RAM, 3.06 GHz

Posted on Nov 16, 2015 3:14 PM

Reply
8 replies

Nov 17, 2015 1:52 AM in response to rkaufmann87

Hi rkaufmann87, thanks for your reply!

Unfortunately, I had a look at the page you referred me to and there's nothing there that actually helps me.

Basically I have a 21.5" mid-2010 iMac (iMac11,2). This iMac shipped with install DVDs, but for some reason the version of AHT was incorrect. More specifically, this iMac requires AHT version 3A195, but the bundled DVDs came with AHT version 3A197 and as a result I can't use the discs to reboot and run AHT.

If I try Option - D at startup the iMac does start the process for doing it online (although it shouldn't because of its vintage) but then returns an error.

So, you see, I'm at a loss except for the fact that I did at one time run AHT on this machine (but I can't remember for the life of me how I actually did it). I would have made notes, but just haven't had the time to go searching for them (although I may find time on the weekend).

Anyway, not sure what else I could do in the meantime, short of finding AHT version 3A195 somewhere to download from etc etc.

Any suggestions/tips/tricks you can offer?

Nov 17, 2015 10:26 PM in response to SeaPapp

Hi Mike, thanks for your help.


🙂


I was able to download it, but seem to have got stuck. There was nothing in the download, but then I realised I probably needed to show hidden files, so I did that via Onyx and could then see what I assume is needed for AHT. However, I couldn't work out how to restore the contents from the download to the /System/Library/CoreServices/.diagnostics folder?


I found some info at: http://rivenbyfive.blogspot.ch/2012/01/download-and-run-apple-hardware-test.html but following the instructions there didn't help me either.


Any suggestions?


Joe.

Nov 18, 2015 3:43 AM in response to Joe Felice

  • Download the AHT for your computer model from the list below.
  • Mount the AHT dmg. Let's refer to the mount point as
    /Volumes/AHT
    .
  • Erase and mount a USB stick. Let's assume its mounted under
    /Volumes/USBstick
    .
  • Copy the AHT to the USB stick and flag it as bootable

cp -r /Volumes/AHT/System /Volumes/USBstick/ sudo bless --folder /Volumes/USBstick/ --file /Volumes/USBstick/System/Library/CoreServices/.diagnostics/diags.efi --label AHT

Insert USB stick in the computer to be tested, boot holding the option key and select the AHT.

Nov 19, 2015 3:27 AM in response to SeaPapp

Hi Mike,


Thanks so much for your help. I feel we're getting closer... 🙂


So, I followed your steps and had no issues (as far as I could tell) with the Terminal commands. But when I booted the computer by holding down the option key, the only other option I got was to boot from the Recovery 10.11.1 partition. If I do that it boots and opens with OS X Utilities from where I can reinstall OS X etc. However there is no AHT option. So I'm guessing that the computer is not actually booting from the USB stick at all.


Am I missing something?


Is there a way for me to copy the AHT into the /System/Library/CoreServices folder of the internal Macintosh HD and running it from there?


Joe.

Aug 11, 2016 4:56 AM in response to SeaPapp

This is the top Apple Support hit for "Apple Hardware Test El Capitan", so although the post is from last year still worth adding to for anyone else who comes hunting like I did.


This may be obvious to some, but not to all readers: the USB stick has to be formatted correctly.


Basically, your USB stick needs to formatted as HFS+, otherwise known as Mac OS Extended, with a GUID partition table scheme.


Almost all USB sticks you might purchase are formatted to allow them to be read from and written to by both Mac and Windows computers, but not in such a way that they can be used as a bootable disk for a mac.


So you could happily copy across the relevant AHT files, but you still won't be able to boot from your stick if the stick is the wrong format.


There's a good step-by-step on how to format your stick correctly, which does not assume any technical knowledge, here: http://www.macworld.com/article/2055589/storage/how-to-format-a-startup-drive-fo r-a-mac.html


If you format your stick as per the article above, then follow the instructions on https://github.com/upekkha/AppleHardwareTest to download and install the AHT on your stick, it should work. Note: should...


I just did exactly that on a 2007 Macbook Pro 3,1 running El Capitan, and the AHT is chugging away on it next to me right how.

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How do I use Apple Hardware Test on mid-2010 21" iMac running El Capitan

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