Filed under: Hardware, Mac 101
Mac 101: Running the Apple Hardware Test software
Is your Mac acting funny? If so, you can use the install disks that came with your machine to test your hardware. To use Apple's Hardware Test (AHT), insert install disk #1 and reboot your Mac while holding down the "d" key on the keyboard (Intel machines only). The AHT software will load and ask for your language -- choose your correct language and click the arrow. From the main menu you can click the "Hardware-Tests" tab. Two tests are available: standard and extended. The standard hardware test will allow you to do a quick, 1-3 minute test of the memory and logic board, while the extended test will run an hour-long test of your system. You can get to the extended test by clicking either a button or check box (this depends on your AHT software version).
Want to see more tips and tricks like this? Check out TUAW's Mac 101 section.
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Reader Comments (Page 1 of 1)
Trevor Price said 11:08AM on 8-01-2008
You can run the test over and over by hitting Control-L to enable looping. This can sometimes help find an intermittent problem.
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Joe Maller said 11:21AM on 8-01-2008
Has anyone ever seen AHT report an error? I've watched it pass machines that could barely run and ended up having defective RAM or motherboards.
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holo said 11:29AM on 8-01-2008
Very rarely...
Also - You guys should note that "d" on startup is an Intel-only trick. PowerPC machines should have come with a seperate AHT disc.
(Some of us are still can't afford shiny new intel machines.. *sigh*)
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aeiou42 said 11:31AM on 8-01-2008
I'm happy to see that Platinum is alive and well.
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Christopher Price said 11:46AM on 8-01-2008
On the newest Macs, you can hold down the F2 key at startup... without any disc at all.
This only works on the MacBook Air, and the latest-gen MacBook Pro, as far as I'm aware. It should work for all future Macs too.
Apple simply copied the EFI-based test disc into the CoreServices folder, enabling the trick in firmware.
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Dinesh said 2:28PM on 8-01-2008
Thanks for the tip. It worked for my Late Feb 2008 MacBook
G said 7:55PM on 8-01-2008
Also works on the 2008 Mac Pro with the D key, no disc.
Rubbinz said 11:58AM on 8-01-2008
Funny you bring this up. Over the last weekend my 20" Core Duo iMac started acting funny and wouldn't stay on for more than 15 minutes. So I ran the AHT and discovered I had a bad power supply and a dead HD fan.
So I ordered up the new parts I needed and went a step further since I was going to have it open and pulled apart. I also swapped out the Core Duo for a C2D and upgraded the HD to a 500GB. Also gave me a chance to replace the other 2 fans and fully clean it out.
She's running super sweet now. Like a brand new machine.
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jesus torres said 12:27PM on 8-01-2008
Macs sold as of 2008 have the test built-in... Restart, hold D.
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Raymie H. said 1:17PM on 8-01-2008
It looks like a holdover from the Mac OS 9 days
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G said 8:04PM on 8-01-2008
Yeah, I love it. From a time when I never imagined running a near-silent eight core Intel Mac with gigabytes of RAM and terabytes of HD space, all insanely more stable and exponentially faster. For less money. As Scotty would say, "How quaint." As long as it works. :)
iamdigitalman said 2:02PM on 8-01-2008
Apple also has copies of the older versions of AHT for the older macs. It's how I got a version for my old Pismo, and burned it to a CD (they are compressed ISOs). Works great. here's the link:
http://www.info.apple.com/support/aht.html
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Pedro Pinhao said 4:58PM on 8-01-2008
I've not been able to run aht on a macbook pro 3,1 with either leopard upgrade dvd or tiger install disc 1
Any idea why?
Thanks
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HandyMac said 3:16PM on 8-29-2008
Because AHT comes in different versions that are model-specific, it's only on the Install DVDs that came with that Mac when new; it's not on general-purpose OS X Install discs.
J-man said 4:46PM on 8-02-2008
HELP! i rely need to run AHT, somthin is definitely up with my macbook :( (summer 07), but i dont have the tiger install disc, and i upgraded to leopard (which deletes AHT!) does anybody know where i can download it? or have another solution? thx for listening
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KA said 12:22PM on 8-03-2008
I'd recommend running the extended test whenever you get a new machine as well – simply because it might have a defect already.
By the way, I was going to run the extended test then go and do something else for the hour it's meant to take, but it only took four minutes!
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