Sago48
Level 1 (4 points)
Desktops

Q: How to reinstall AHT on my iMac early 2008

My imac 8, 1, early 2008, now has Yosemite installed, after Leopard and then Snow Lepoard. AHT will not load with option D or the nline version, ans as I don't have the original disks so I don't seem to be able to perform the test. Is there somewhere I can download and install AHT from?

 

I suppose my 2nd Q is does this matter? Are there better/easier ways of testing the mainboard etc?

 

Thanks.

 

PS. I had to type my Q 3 times to get to this point. 1. Type Q and then login; 2 type again; 3. Q appears in summary box so edit down and then type again below summary box. 

iPhone 4S, iOS 6.1.3

Posted on Feb 4, 2016 11:43 PM

by Mike Sombrio,Apple recommended
Mike Sombrio Mike Sombrio
Level 6 (17,234 points)
Apple Watch
A:

I've not tried this but you have nothing to lose.

How to run AHT w/o the system discs

 

1) SHUT DOWN the computer (Don't RESTART... shut it down)

 

2) Hold down the OPTION + D keys

 

3) Press the Power Button (make sure to hold down the OPTION + D keys first)

 

4) Continue to hold down the OPTION + D keys until the system enters AHT mode

 

5) Let the app verify the hardware setup before initiating the test.

 

6) There are two testing modes. To select the "Extended Test" activate the check box below the Test button.

 

7) Press Test button to begin test


If that doesn't work you can look here to see if your version is available https://github.com/upekkha/AppleHardwareTest

Posted on Feb 8, 2016 1:17 PM

Close
Sago48

Q: How to reinstall AHT on my iMac early 2008

  • All replies
  • Helpful answers

Previous Page 2

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Feb 10, 2016 3:57 PM in response to Sago48
    Level 6 (17,234 points)
    Apple Watch
    Feb 10, 2016 3:57 PM in response to Sago48

    Still not seeing anything in the Snow Leopard report with the exception of a long run time for EtreCheck and you're using torrent software, you should stop that.

    Run Disk Utility from either the Snow Leopard install disc or from the recovery partition, Command-R at startup, and repair the disk, not the seperate partitions but the entire disk. See if that helps.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 10, 2016 5:14 PM in response to den.thed
    Level 5 (7,559 points)
    Notebooks
    Feb 10, 2016 5:14 PM in response to den.thed

    den.thed wrote:

     

    You can not download the AHT from Apple or the internet.

     

    To run the AHT you need disc #2 that originally came with your iMac.

     

    Your best bet is to contact Apple Support and order a replacement disc set.

    Contact Apple for support and service - Apple Support

     

    I'm adding this post here because the AHT images are available for download as Mike Sombrio pointed out lower down.

    NOTE: some links on the github page are not on Apple.com, I would only use the links that are on Apple's download site, otherwise it could be malicious.

     

    I made a shell script to image AHT onto a USB drive - it is the easiest way I found to create a bootable USB AHT disk. Installing into the .diagnostics folder never worked for me.

    It is very basic - you can get away with just copying the .diagnostics folder to a HFS+ disk, otherwise see…

    https://gist.github.com/drewreece/2e5eed7dbfbd5dd7e929

    Or burn the dmg to a CD (AHT rarely worked for me on CD).

    My script does bless the system for use on next boot, YMMV.

  • by Sago48,

    Sago48 Sago48 Feb 11, 2016 12:14 AM in response to Mike Sombrio
    Level 1 (4 points)
    Desktops
    Feb 11, 2016 12:14 AM in response to Mike Sombrio

    Thanks Mike. I've already run Disk Utility from the recovery disk but will repeat.

     

    What effect does torrent software have? I know it can be disguised malware but over the it has been handy for getting things that're hard to find. I don't think it's active and it seems to be blocked or whatever it's called these days but will make sure.

     

    Drew I don't quite understand your post - I have installed the AHT from Github following Mike's guidance and run it successfully, with no problems identified.

  • by Sago48,

    Sago48 Sago48 Feb 11, 2016 2:22 AM in response to Mike Sombrio
    Level 1 (4 points)
    Desktops
    Feb 11, 2016 2:22 AM in response to Mike Sombrio

    I've re-run disk utility from the recovery disk and all seems OK. I'll increase the ram to 4 gigs and see if that improves things. Am I right ot assume that Crucial ram will do the job?

     

    Thanks

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Feb 11, 2016 3:47 AM in response to Sago48
    Level 6 (17,234 points)
    Apple Watch
    Feb 11, 2016 3:47 AM in response to Sago48

    Crucial ram is one of the recommended brands, but I'm still not sure that's the only problem. I'm going to see if I can get etresoft, the developer of EtreCheck to look at your report and offer his expert opinion.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 11, 2016 6:05 AM in response to Sago48
    Level 5 (7,559 points)
    Notebooks
    Feb 11, 2016 6:05 AM in response to Sago48

    Sago48 wrote:

     

    Drew I don't quite understand your post - I have installed the AHT from Github following Mike's guidance and run it successfully, with no problems identified.

    Mike's post doesn't explain how to install anything, he is telling you how to use a version that is available via the internet, it is not the same as installing.

    Startup key combinations for Mac - Apple Support

     

    I found certain models to be very fussy with AHT, so it is great that you got it running over the internet. I was posting to help you and others who inevitably read after seeing similar issues & follow the same steps etc.

     

    Good luck with it.

  • by Sago48,

    Sago48 Sago48 Feb 11, 2016 11:00 PM in response to Drew Reece
    Level 1 (4 points)
    Desktops
    Feb 11, 2016 11:00 PM in response to Drew Reece

    Drew, to help me understand this I'm setting out what I did to enable me to use the AHT.

     

    Following Mike's Github link I opted to try to add the appropriate (for this iMac 8,1) .diagnostics file to system/library/coreservices first, and to try the USB/shell approach second if the first didn't work. In fact it took 2 attempts to add the .diagnostics file as the first one didn't enable the AHT. Once added successfully this is what the files list as:

     

    file:///System/Library/CoreServices/.diagnostics/CommonAHTResources/

    file:///System/Library/CoreServices/.diagnostics/diags.efi

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/.DS_Store

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/apple_hardware_tes t.acm/

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/diags.efi

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/diags.env

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/GUI/

    file:///System/Library/CoreServices/.diagnostics/Mac-F226BEC8/Runtime_Files/

     

    I was then able to access AHT on restart by holding down the D key.

     

    If I understand correctly the above files are not the actual AHT, but a link to an online copy?

     

    In parallel approaches Apple are now sending me replacement original disks and Mike is also looking at the Etretest results.

     

    Thanks.

  • by Drew Reece,

    Drew Reece Drew Reece Feb 12, 2016 11:54 AM in response to Sago48
    Level 5 (7,559 points)
    Notebooks
    Feb 12, 2016 11:54 AM in response to Sago48

    Sago48 wrote:

     

    If I understand correctly the above files are not the actual AHT, but a link to an online copy?

     

    No the 'D' at start up only looks at the local disk - you have indeed managed to install Apple Hardware Test onto the boot disk - congratulations

     

    I read Mike's post & assumed you followed it to the letter - 'option+D' is internet based AHT. 

    I didn't take into account the upekkha guide on github, sorry for the confusion I caused.

     

     

    The original install disks are useful if you have a failed HD, so it is good that they are on their way to you.

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Feb 13, 2016 7:37 AM in response to Sago48
    Level 6 (17,234 points)
    Apple Watch
    Feb 13, 2016 7:37 AM in response to Sago48

    Sago48, etresoft, the developer of the EtreCheck program looked at your report and feels that only 2Gb of ram is your biggest problem. Upgrading your  ram looks to be the best solution.

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Feb 13, 2016 10:33 AM in response to Drew Reece
    Level 6 (17,234 points)
    Apple Watch
    Feb 13, 2016 10:33 AM in response to Drew Reece

    I want to pass along these suggestions from den.thed who also looked at your report and has followed along as we work through your problem:

     

    1. I think that you are correct in suggesting more RAM for the fathers system.

     

    2. Testing out El Cap. on a second partition may have actually caused Snow Leopard to run less efficient, because now it has less free space to work in.

     

    3. FWIW, I think that they (father and son) need to decide on one OS X or the other.

     

    4. Personally, I would loose the second partition, then:

     

    A. if I was staying with Snow Leopard I would get rid of the failed Startup Item, some User Launch Agents, those User Login Items, plus most of the Internet Plug-ins

     

    B. if you decide to run ElCapitan you should probably back up your Snow Leopard, reinstall a fresh copy of El Cap then migrate from the back up using set up assistant. Don't set it up and then migrate as you could end up with some of his files not where you expect them. Migrate as soon as El Capitan starts up and asks you to.

  • by Sago48,

    Sago48 Sago48 Feb 13, 2016 10:38 AM in response to Mike Sombrio
    Level 1 (4 points)
    Desktops
    Feb 13, 2016 10:38 AM in response to Mike Sombrio

    Thanks Mike. I usually opt for crucial ram but do you have a view on what is best overall? Crucial can offer 2 x 2gb for c£46 inc. postage. And I gather it's possible to run 6gb  - 1x4 and 1x2. But the Crucial DDR2 800 4gb is costly so maybe not wise. Might there be better deals?

     

    I see that a ram increase for this iMac is easy to do but I wonder about the processor - I see it's a zif socket so I imagine that would be doable? I swopped the Core duo on my old mini for a core 2 duo and upgraded the firmware allowing me it install 4gb ram all used. This gave me a niftier machine for a while, though Snow Leopard was the last OS I could install, despite online claims of workarounds.

     

    Thanks

     

    John

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Feb 13, 2016 11:01 AM in response to Sago48
    Level 6 (17,234 points)
    Apple Watch
    Feb 13, 2016 11:01 AM in response to Sago48

    I would spend the extra for Crucial, or if you can find OWC ram through Amazon.com that's good ram also. I would avoid other brands that may cause kernel panics. If you decide to stay with Snow Leopard 4Gb will probably suffice but if you decide on El Cap you'd be wise to have 6Gb. Getting inside an iMac isn't easy and with wires and connectors cooking in there for eight years and possibly becoming brittle I don't think it's worth the risk, effort or cost to upgrade the processor.

Previous Page 2