# Use Apple Hardware Test and other diagnostics to test for hardware



## Giaguara (Apr 18, 2008)

If you suspect your Mac might have a hardware failure, you can use the bundled Apple Hardware Test that came with your Mac. 
These tests are model specific, so using the discs of your PowerBook on your Mac Pro will not work. 

If you get odd graphical errors, shutdowns, applications crash with or without a pattern, or there is some other behavior that makes you suspect the hardware, testing it is very easy. 

On an *Intel based Mac*, insert Mac OS X Install disc 1 that came with your Mac to your Mac, and hold letter *D* at boot. This will load it to the hardware test. 
After language selection, use *ctrl-L* keyboard combination to get it to loop mode, and select extended test, and let it run at least for a few hours. You can end the test with the same keyboard combo, or it will stop if it finds an error.

For testing graphical or RAM errors, it is best to run the test at least for the evening, or even better to let it run the test overnight. If you will receive an error message on the screen, this will indicate where the error lies. (In doubt, post the error here and someone will find out for you). 

For *PPC based Macs*, use the Install Disc 1 that came with your Mac, hold down *alt* or *option* key depending on your keyboard, select the Hardware  Test from the menu, and the menu selections and loop mode are as for Intel based Macs.

If you don't have those install discs available, and suspect faulty RAM you could run Memtest. Memtest is an option also when you have the discs if you need to test your RAM. There is a Windows version out there, and a Mac version http://www.memtestosx.org.


----------



## dq101 (Apr 20, 2008)

Cool I didn't know that I just use the Apple PPC test cd or whatever it's called.


----------



## DeltaMac (Apr 20, 2008)

Recent Intel models don't need a disk at all. Just reboot holding the D key.


----------



## Diver_Dan (May 17, 2008)

Hi,

I just registered as I've been receiving kernel panic errors on my Mac Pro (quad core version 1,1). I ran the Apple Hardware Test and got this error message:

4MEM/40/40000001 : B:1 C:[a string of symbols and letters] R:0

I assume this is a RAM error, but I don't know how to determine which stick is faulty. My current RAM configuration is a pair of 512MB sticks in DIMM 1 & 2 on Riser A, and a pair of 1024MB sticks in DIMM 3 & 4 on Riser A.

Can someone help me with this diagnostic?

Thanks,
Diver_Dan


----------



## Satcomer (May 17, 2008)

Yep. You will something more capable to test RAM. You need something like Rember(with a link to MemTest).


----------



## DeltaMac (May 17, 2008)

Or, try swapping the two 512 chips on the same riser. Run the test again. If the failure is the same, try swapping the 1GB chips, then run the test again.
Also, a memory error will sometimes show up in your System Profiler, under the memory tab, or the Diagnostics tab might also show a memory error, listing the (sometimes cryptic) memory location.
You can also try swapping one pair into the other riser, then run the test again.
Or, removing one pair completely, then check the test again, then remove that pair, and test again with just the other pair installed.
Be prepared to accept that reseating the memory may fix the error. It might not ever recur, or could be just a temporary fix. The memtest utility can be helpful, too.


----------



## Texas Mac Man (May 27, 2008)

If you don't have a Apple Hardware Test CD, you can download the software for some model Macs at the site below. Then you can burn a CD.

*Apple Hardware Test Images and Information*
http://www.info.apple.com/support/aht.html

Cheers, Tom


----------



## uxp (Aug 8, 2008)

Sorry to be bumping an old thread, but I really hate how Apple requires you to use certain hardware in order to run a Hardware Diagnostics. My MBP's Superdrive is going downhill, and I wanted to see what exactly what was going wrong, so After I tossed in the Install Disk and rebooted, I came up with no errors. Great. 

I rebooted, holding the mouse button, and i could hear the drive ejecting, but no disk came out. After OS X loaded, i tried to eject, and same thing, sounds but no disc. Now I have my install disk stuck in my drive, sucking my battery, and no way to get it out.

For all you peeps, I've tried forcing an eject through the shell, every time I reboot, and any other method I've heard of. It seems to be a mechanically broken drive.


----------



## Texas Mac Man (Aug 8, 2008)

uxp, look at these links.

*A dozen ways to eject or unmount a recalcitrant CD or DVD*
http://www.osxfaq.com/dailytips/08-2002/08-12.ws

*Ejecting media in Mac OS X: Removing 'stuck' CDs/DVDs*
http://www.macfixit.com/article.php?story=20041011075232575

*PowerPC-based Macintosh: How to eject a disc when other options don't work*
http://docs.info.apple.com/article.html?artnum=106752

Cheers, Tom


----------



## uxp (Aug 8, 2008)

Thanks for the link Tom, but it looks like my only option is to head into the Apple Store and get my drive replaced. I'm guessing that there is a catch mechanism inside the drive that isn't being properly released. 

All those options result in the same exact thing: the drive ejects the Disc, but the disc doesn't come out.


----------



## Satcomer (Sep 16, 2008)

Also for anyone the new single user program AppleJack that is now Leopard capable is out. It is really worth it.


----------



## eagledavid (Dec 7, 2008)

The first time I ran the hardware test, I got this error message:4HDD/11/400000004, with an instruction to disconnect any peripherals and run the test again. I disconnected my external drive and ran it again. This time, no errors were found. Should I draw the obvious conclusion that there is a fault in the external drive? If so, is there any alternative to replacing it?
Thanks


----------



## DeltaMac (Dec 7, 2008)

No, a failed test with an external device (that is not supported directly by the test) does not necessarily mean that device is bad. It simply means that test failed, but the test may not support that device anyway. The Apple Hardware test is only designed to test the Apple hardware....

Are you having problems with that drive?
Does that external drive pass a test through your Disk Utility/Repair Disk?


----------



## eagledavid (Dec 7, 2008)

Yes, I am having trouble with the external drive -- it is clicking 3 or 4 times each minute or so, and I can't seem to get it to mount, so I can't run Disk Utility repair to test it.
My iMac G5 has been behaving very erratically recently -- frequent freezes, difficulty restarting --- but has passed Disk Utility, Applejack and Tech Tool tests. Is it possible that a defect on the external drive could be causing this?


----------



## DeltaMac (Dec 7, 2008)

eagledavid said:


> ... If so, is there any alternative to replacing it?
> Thanks



Sounds like that external is having problems....
If Disk Utility won't do much, then you may want to try a more-capable repair utility. You said you tried Tech Tool Pro? IS that a recent version - maybe a version that came with your AppleCare with this Mac? What's the results with TechTool Pro?
If you don't get anywhere with that, and your drive is intermittently clicking, then it may be time to replace it. If you have important files on that drive, then you should find another utility to try, such as Disk Warrior.
If you can't borrow a copy from someone, you would need to purchase that. It's some good software to have for emergencies, but if it doesn't help you with this drive, then that's a hard choice, I suppose.
Replacement drives keep getting cheaper, however.....


----------



## eagledavid (Dec 8, 2008)

I finally managed to mount the drive, Disk Drive repair indicated no problem, Tech Tools would not recognize the drive, so I have given up and will buy a new drive. The old one contains a Super Duper back-up and my Time Machine one-year back-up; if I have to lose the latter it's no big deal I guess.

I have ordered Disk Warrior.

I appreciate your help


----------



## rflanery (Jan 28, 2009)

Hello,

On my dual 2.7 PPC G5 (osx 10.4.11) I'm getting an "Error Detected" on the "Memory" section of the Apple Hardware Test.  

Here's the error code I'm getting:  2MEM/104/4IMM0/J11

Has anyone seen this before?

I've tried swapping out different memory sticks and still the same error.


----------



## rflanery (Jan 28, 2009)

sorry i mean 2MEM/104/4: DIMM0/J11


----------



## fryke (Jan 28, 2009)

You didn't just swap them around, you took out half of them and then the other half to determine in which pair the problematic DIMM is, right? If it doesn't matter at all which DIMMs are installed, I fear it's rather logicboard/riser-related than DIMM-related.


----------



## rflanery (Jan 28, 2009)

Yeah I've tried both halves of the DIMM slots, same issue across the board.  Yes, I was fearing Logic Board issues... Thanks!


----------

