Most Mac users will experience years of using a Mac without any problems. But every so often, a hardware issue could surface that could significantly impact how your Mac performs.
Identifying the cause of problems — hardware or software — is the first step to fixing them. It could make a trip to an Apple Store or certified reseller easier knowing you've done all you can to identify and whenever possible, fix the problem yourself — saving you downtime and a potentially costly repair.
Built into every Mac is a way to run an Apple Hardware Test, also known as an Apple Diagnostics.
Essentially, a Mac hardware test is the great tool to help you understand the problem. And if it doesn't have a fix for it — there are more advanced tools that you can use to troubleshoot Mac issues. More about that in a moment. How to run Mac diagnostics. Quickly determine the condition of the drive in your computer with this comprehensive, easy-to-use diagnostic. View Support Information Download for Windows DOWNLOAD FOR USB NOT AVAILABLE FOR MAC Legacy Tools Download.
Hardware Tests are an effective way to identify the cause of a Mac performance problem, which could be CPU or GPU issue, a failing disk drive, an overloaded memory, a fan overheating, or any number of other potential faults. If you suspect it’s a hardware problem, Hardware Tests are the way to troubleshoot on Macs built before 2013. In newer models, those built after 2013, those same tests are labelled Apple Diagnostics.
How to Run Apple Diagnostics on any Mac
In some cases, a hardware problem is so severe that you won’t be able to switch your Mac back on. Thankfully, if you can run an Apple Diagnostics or Hardware Test, Apple Support suggests this is a way you can restart your Mac, even if it refuses to switch back on through other means.
Whether you are running an Apple diagnostics (on newer hardware and OS X devices) or a Mac hardware test (on older devices), Apple recommends printing their support instructions on how to run these tests. Once you’ve got the instructions in front of you, Apple recommends going through the following process to diagnose a hardware problem:
- For those with iMacs or any desktop-based device: Disconnect all external drives and hardware devices, except for the keyboard, mouse, display, and speakers.
- Select Apple Menu > Restart.
- Press and hold the D key when the Mac is restarting.
- Apple Diagnostics will run automatically. When it is complete, it will present a list of the problems encountered.
Common Mac Hardware Issues
At this point, you can either follow on-screen instructions or contact Apple Support — arranging a Genius Bar appointment — or go to an Apple Authorized Service Provider to make repairs, to fix the problems. Make a note of any reference codes.
Some of the most common hardware error codes indicate problems with:
- Wi-Fi — a failure of the AirPort wireless card (4AIR);
- Hard disk and SSD (4HDD)
- Logic board (4IRP)
- Memory — RAM (4MEM)
- External disk (4MHD)
- Fans (4MOT)
- Processor (4PRC)
- Video/graphics card (4YDC)
Most Mac error codes suggest a failure of the component they reference, or a related component that is causing a problem with the hardware. In most cases, an Apple specialist or technician may be needed to resolve this issue.
However, before you send your poor, unhealthy Mac off to the shop, there are several fixes you could try at home, such as resetting the PRAM or SMC. This can fix some of the most common errors, including problems with the logic board and fan.
Disk Utility (built-into every OS X) is useful for fixing memory (RAM), hard disk and external drive problems, as are several third-party apps.
For those with older Macs, when you are running an OS X Hardware Test, an alert message will appear once complete with a list of the problems encountered. Again, you have the option of following on-screen instructions to restore the Mac, or re-booting the device using a startup disk, or taking the Mac to a store or Authorized Service Provider.
In any scenario involving hardware, you need to be aware that you are at risk of losing any items on your Mac that haven't been backed-up to the cloud. We recommend storing as much as you can with a cloud provider, such as Dropbox, or Apple iCloud.
Another way to improve Mac performance
What happens if you run a Mac diagnostics and it comes back with nothing? Does this mean you need to buy a new Mac? Or give up using Mac altogether, switching to another device and operating system?
An Apple Diagnostics or Hardware Test that reports a lack of problems indicates it could be a software issue. Another alternative worth exploring, especially if your Mac is overheating or slowing down, is that your storage is too full of junk, clutter, applications, and duplicate files and photos.
On average, Mac users have 62GB of data, files, apps, and images they do not need. Too many files slow down and overheat computers, making them difficult to use and causing them to crash more often.
CleanMyMac X is designed to clear up junk, clutter and get your Mac back to peak performance. With over 4 million downloads and hundreds of positive reviews, we know that CleanMyMac X has carefully removed over 11 million unnecessary apps and over 2.5 billion gigabytes of data clogging up Macs all over the world.
With two click removals, you can quickly clean loads of data, making your Mac easier to use and freeing up space for new documents, downloads and images. Once you've run a Hardware Test or Apple Diagnostics, use CleanMyMac X (it's free to try) to identify and fix any other issues that are causing your Mac to run slowly or overheat.
We hope this article was helpful and you found the answers to all your questions here. Stay tuned!
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I have put together a list of what are, in my opinion, the ten best Mac disk repair software and other excellent Mac tools for troubleshooting, diagnosing, and repairing a Mac. Many of them are free or offer a free trial. As Macs continue to gain market share, there is an increased likelihood that you will have to support them if you are a tech. And even if you aren’t a tech, it’s good to know which tools are the best to use when it comes time to repair your own.
Mac OS from Apple WWDC2019
In-page jumps:
Disk Warrior Trial
Free Mac Disk Repair Software
Drive Genius – is it the Best Mac Repair App
Introduction to our Top 10 Mac Repair Software
Did you know there are several Mac disk repair options that each function differently and one may suit your needs better than another? I detail several for you below so you can decide.
More than just a list of disk repair software, I provide many Mac software solutions for you and your clients! Even better, some are free!
Want to clone a Mac drive? Want to monitor a Mac’s hardware sensors? Want heroic system recovery for mere mortals?! Oh, there are some great software here! Read on.
TechTool Protogo
TechTool Protogo is a Mac repair program suite which contains three of Micromat’s best Mac repair tools; TechTool Pro 8, TechTool Pro Classic, and DiskStudio.
Protogo creates a bootable Mac repair toolbox with these tools as well as any of your own tools on a portable hard drive or flash drive.
You can then boot from this drive, bypassing the OS, and run diagnostics on a computer to determine problems.
Protogo also allows you to repair and recover data from problematic hard drives as well as defragment, optimize, and securely delete data.
Cost: $129.99
Memtest OS X
Memtest OS X is a memory testing program for Mac OS X. It is a command line utility so it can be ran in OS X or in Single-User Mode if your Mac will not boot.
It is great for testing intermittent system problems when you are having trouble determining if it is a memory problem.
If you prefer memtest with a GUI front-end, then be sure to check out Rember.
Rember will run in OS X but will not work in Single-User Mode so Memtest OS X is the better option.
Cost: $1.39
Mac Disk Repair – DiskWarrior 5
Disk Repair for Macs – DiskWarrior utilizes a unique disk repair method for Macs
DiskWarrior is arguably one of the best hard drive repair programs for the Mac.
It works differently than other data repair programs.
Instead of trying to rebuild the damaged data itself, DiskWarrior builds replacement data based off of the original data.
It then verifies the new data structure based on the original to make sure it is error free.
You can also use DiskWarrior as a preventative maintenance utility for hard disks.
When run, it rebuilds your directory eliminating any damage that you may not be aware of. It also optimizes the directory for better performance.
Cost: $99.95 but look for a trial.
If it is more serious and your Mac’s hard drive has crashed, I have provided an extensive data recovery guide with a list of Hard Drive Recovery Tools in my article How to Recover Data from a Crashed Hard Drive.
First Free Disk Repair-Mac – OnyX
Onyx is a maintenance, optimization, and personalization utility for Mac OS X.
It allows you to run hard drive diagnostics, run system maintenance tasks, delete caches, and configure tons of OS X hidden features.
Even if you aren’t using it as a repair utility, it is a great application to help keep your Mac running in top shape.
Diagnostic Tool For Cars And Trucks
Cost: Free!
Mac Data Rescue
Data Rescue is a data recovery program that focuses purely on recovering data from corrupt drives instead of hard drive repair.
It scans the corrupt drive analyzing all of its contents and allows you to choose which data you would like to recover.
It even scans for deleted files. Data Rescue II restores the data to a separate drive leaving the original data intact.
It comes with an emergency boot CD that you can use to recover data when the computer will not boot and it also works on drives that won’t mount.
Cost: $99.00
AppCleaner
AppCleaner may not be classified as a repair tool but it can be used as one.
When you are having trouble with an application in OS X, you can simply remove it by dragging it to the Trash.
However, this still leaves behind the applications preferences, caches, and other files that could still cause the same problem after you reinstall it.
AppCleaner will remove all of these files making sure that the app is completely gone before you attempt a reinstall.
Interesting interface!
Cost: Free!
Drive Genius – Is this the Best Mac Repair App?!
Drive Genius is a disk utility application for Macs.
Its main features include:
- defragmenting,
- running benchtests,
- directory repair,
- integrity checks,
- surface scans,
- repartitioning,
- cloning,
- shredding data, and more.
With all these features, you can see why I ask is it the best Mac repair app overall!
This is actually the same program used to defrag Macs at the Genius Bar in Apple Stores.
Oh yes, Apple uses it.
Drive Genius also comes on a bootable DVD so you can run it even when a Mac will not boot.
Cost: $99.00
Mac Backup – Carbon Copy Cloner
Carbon Copy Cloner is a simple yet very effective backup utility for the Mac. Like most other backup utilities, it can be scheduled to backup your Mac on a regular basis.
The best part, however, is its ability to completely clone a hard drive with it still being bootable.
This tool comes in very handy when you are replacing hard drives, setting up multiple Macs, or recovering from a system crash.
Carbon Copy Cloner is donation-ware so you can download it for free without any restrictions.
Maybe you will be so pleased you will buy them a coffee anyway!
You can also check out SuperDuper which has more features but costs $27.95.
However, if you just need a simple backup and cloning utility, Carbon Copy Cloner does a great job.
Cost: Free! (donation-ware)
Apple Mac Disk Repair – AppleJack
AppleJack is a troubleshooting utility for Mac OS X. It runs under Single-User Mode so it can be used even when OS X will not boot.
AppleJack will repair disks, repair permissions, cleanup cache files, validate preference files, and remove swap files.
You can select these tasks individually or have AppleJack run all of them and even reboot when finished.
Unfortunately, at the time of writing this article, AppleJack is not yet compatible with Leopard but a new version is in the works. Be sure to check their page frequently for an update because this is an invaluable tool.
Diagnostic Tool For Mercury Motor
When I updated this article for 2020, I checked on SourceForge and there were over 600 downloads last week!
Cost: Free! (open-source)
Hardware Monitor
Hardware Monitor is a utility that allows you to view data from the hardware sensors in a Mac.
It currently has support for temperature readings, battery data, voltage, current, fan speed, power and load, ambient light, as well as user-defined artificial sensors.
It’s a great utility to use when simply trying to find out if your hardware is malfunctioning.
Cost: € 7.00 (can also be purchased with U.S. Dollars)
Also consider
OSX disk repair
This is kind of a nice segway into handy hardware tools and toolkits. Click on the following link if you want to see some great ideas on what I recommend for your Mac or PC Repair Toolkit.
As you may know, I believe your should support Macs in your Computer IT Consultant Business. I state my case here in my article on Why You Should Support Macs With Your IT Business.
Well if you were counting, that is 4 totally free Mac OSX disk repair utilities, and one so cheap it may as well be free!
The best Mac repair disk software may well be a paid one depending on your exact needs, and I’ve shown you my pick for the best of those too.
If you know of other great Mac software let me know in the comments below. What Mac OS X repair tools do you like? Is there another Mac Disk Repair utility you’d suggest? Please leave a comment to help others, or if the above tools have helped you.
And as for hardware, click this link if you want to repair hard drive-Mac for more details.
Citrix Receiver Diagnostic Tool For Mac
Summary of Best Mac Repair Software:
Excellent Mac disk repair software is provided above, for you to consider and try their features for yourself. I didn’t stop there. This list contains some other handy Mac software I consider to be the best tools for techs and Mac owners.
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