Troubleshoot your misbehaving Mac with Apple’s Hardware Test
Posted by Lab Rat
On those rare occasions when a Mac starts acting a bit uppity, most of us turn to Apple’s Disk Utility as our first attempt at setting things straight. If Disk Utility cannot repair the problem, our next step is usually a 3rd party disk repair utility such as Alsoft’s Disk Warrior. However, there are times when the problem doesn’t stem from faulty software or hard disk corruption. Sometimes the problem can lie in the hardware itself.
If you are experiencing frequent kernel panics or random shut downs, perhaps it is time to take a look at the little-known (and free) Apple Hardware Test app that ships with every Mac.
As most people know, rebooting your Mac from the software restore CD that comes with your Mac by holding the “C” key during will allow you to run Apple’s Disk Utility app. However, if you restart your computer with that same disk in your DVD drive and hold down the “D” key, you will be treated to a bit of nostalgia in the form of Apple’s Hardware Test. (Note: AHT will not run from a standalone OS X DVD, only the software restore DVDs that ship with each Mac).
Apple Hardware Test may seem like Disk Utility’s ugly step-sister, but it serves an entirely different purpose. Looking very OS 9-ish, the Apple Hardware test allows you to run a series of tests on your system’s RAM, logic board, modem (if present) video RAM, and Apple’s Airport Card. It will not test 3rd party video cards, PCI cards, or Non-Apple devices, but you should have tried trouble-shooting those devices already by this point.
There are very few options to choose when running AHT, in fact there is only one. You can either choose to run the basic test, or check the “Perform extended testing” check box. Apple warns using this option will take considerably longer, and depending on how much memory you have, it does make a difference. The basic test on our Mac Pro with 4 GB of RAM took about 4 minutes, the extended test took about 20.
Apple Hardware Test also consists of a version of the Apple System Profiler, and allows you view your computer’s memory configuration, video card info, active communication ports, and basic system info such as your serial number, Boot ROM version, and model number.
All in all we think AHT is a very simple and well designed diagnostic tool that more people should be aware of, and one that all people should add to their trouble shooting arsenal.
March 29th, 2007 at 10:52 pm
wow, that DOES look old-school. Takes me back. It’s funny to think there are Mac users out there now who never even saw OS 9!
March 31st, 2007 at 9:16 pm
Never knew about that, thanks!
April 1st, 2007 at 9:02 am
you know you can loop it too
April 1st, 2007 at 9:03 am
control - L
April 1st, 2007 at 8:18 pm
Pretty dam cool.
April 1st, 2007 at 8:24 pm
Also check the following video for more mac os x tools that could help you monitor the performance of your mac:
http://www.mostofmymac.com/articles/useful-tools-from-the-utilities-folder/
April 2nd, 2007 at 12:13 am
Actually AHT doesn’t even test the disk so it’s not very fair to compare it to Disk Utility. It’s also not very useful as maintenance software since if it reports a problem, generally the only way to remedy that problem is to replace a component.
April 2nd, 2007 at 7:16 am
Tong, when do they say to use AHT instead of diskutility? They are merely saying it can help pinpoint hardware issues diskutility can’t. Use both if you have a problem. There is room for all.
April 2nd, 2007 at 8:34 am
how do you start the hardware test?
April 2nd, 2007 at 9:59 am
What’s crazy is I’ve been instructed to run this before by AppleCare. It has no fan controllers (at least not on the iMac G5), so the cooling fans crank up to full blast!
April 2nd, 2007 at 12:55 pm
thanks for it , Lab Rat
April 16th, 2007 at 8:22 pm
“It’s funny to think there are Mac users out there now who never even saw OS 9!”
It is good there are users who never saw OS 9.
I’m glad that by the time my kids are grown up, they will never have had the same trouble users had with earlier operating systems (OS 9 and less, Win ME and less).
November 15th, 2007 at 11:38 pm
Thanks… it’s hard to find information on this utility out on the web. One difference for iMac G5s is that you hold down “option” instead of “d” at boot.
Thanks too to Charles… I was wondering why the fans went crazy!
July 21st, 2008 at 6:30 pm
Sure hope you guys are still following this discussion. I’ve downloaded the Apple Hardware test for iBook, have a tangerine clamshell iBook running OSX.3 and having problems with the Airport card, computer not recognizing, telling me it’s not installed. I would like to run the hardware test to check the Airport drive, if that’s possible prior to sending back the card, taking the chance that the card is O.K. and being charged a fee for this. Any suggestions are helpful. Just really want to use this for a wireless connection because I was down for an entire week, thanks to Verizon’s inability to service it’s customers in timely manner. I’m a graphic designer and depend on my Internet connections. Thought this would be a quick fix, as opposed to running to the local library, waiting to use their system, dealing with screaming kids (by the way — what happened to the idea that the library is supposed to be a quiet place???), only having 45 minutes to do 8 hours of work, etc. blah so-on ….
Cathy
October 7th, 2008 at 2:35 pm
I just ran the hardware test, and when it got to testing the video ram, a strange multi-colored pattern overtook the screen. It scared me and I aborted the test. Is this normal?