Mac Troubleshooting Guide

Last Updated: Oct 09, 2020

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macOS is a reliable operating system, but from every so often it has an issue and requires first aid. In this article, I will show you how to fix common Mac problems, such as a slow system, a spinning beach ball, crashing or unresponsive applications and more.

When I left the Microsoft world behind me by switching from Windows to macOS, I’ve become more productive and have experienced fewer issues with my computers. But nothing is perfect, not even Apple and from time to time your Mac may act up, and you have to troubleshoot it.

By acting up, I mean macOS may become unresponsive or slow, or certain apps may crash. Most of those issues can be fixed fairly quickly by following the steps outlined below. Those steps are what Apple support will likely make you go through when you call or tweet them.

So to save time, you can go through them yourself and if the problem still can’t be fixed, call Apple support and tell them that you’ve already performed those steps.

How To Fix Common Mac Problems

Please note that not every problem requires you to go through all of those steps, especially the more invasive steps 8-10.

  1. Reboot Mac
  2. Reset PRAM/NVRAM
  3. Boot into Safe Mode
  4. Reset SMC
  5. Repair disk permissions
  6. Verify disk (and repair if necessary)
  7. Reset Safari and clear caches
  8. Delete Caches folders
  9. Update to the latest version of macOS
  10. Create a new user account
  11. Reinstall macOS

1. Reboot Mac

Depending on the issue you are facing, a reboot is often the simplest fix. That is particularly the case when an individual application is misbehaving. Macs typically reboot quickly, so that’s the first step I recommend doing.

2. Reset PRAM and NVRAM

What are PRAM and NVRAM? From apple.com:

Your Mac stores certain settings in a special memory area even if it is turned off (unless there is a battery issue as described below).  On Intel-based Macs, this is stored in memory known as NVRAM; on PowerPC-based Macs, this is stored in memory known as PRAM.

Mac First Aid - How to fix common Mac problems
Reset PRAM – Key combination

To reset PRAM and NVRAM perform the following steps:

  1. Turn off your computer.
  2. Turn on the computer.
  3. Press and hold the Command-Option-P-R keys before you hear the startup sound.
  4. Hold the keys down until the computer restarts, and you hear the startup sound for the second time.
  5. Release the keys.

To learn more about how to reset NVRAM on your Mac, see this Apple support article.

3. Boot Into Safe Mode

To boot into Safe Mode, restart your Mac and immediately press and hold the shift key until you see a progress bar at the bottom of the screen. That’s an indication that your Mac is booting into Safe Mode, which deletes a couple of additional caches. Once in Safe Mode, reboot normally, without holding the Shift key.

To learn more about Safe Mode, check out this Apple support document.

4. Reset the System Management Controller (SMC)

Resetting the SMC requires different steps, depending on if you are on a desktop (i.e. iMac or Mac Mini) or MacBook. Below are the steps for both platforms:

How to Reset the SMC On a Desktop

  1. Power down your Mac.
  2. Unplug the power cord.
  3. Wait for 15 seconds.
  4. Plug the power cord back in.
  5. Wait five seconds, then press the power button to turn on your Mac.

How to Reset the SMC On a MacBook With a Non-Removable Battery

  1. Power down your MacBook.
  2. Unplug the MagSafe or USB-C power adapter from the MacBook.
  3. Using the built-in keyboard, press Shift-Control-Option on the left side of the keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.*
  4. Release all keys.
  5. Reconnect the power adapter.
  6. Press the power button again to turn on your Mac.

*If you have a 2016 MacBook Pro with Touch ID, the Touch ID button is also the power button.

To learn more about resetting the System Management Controller (SMC) on your Mac, check out this Apple support article.

5. Repair Disk Permissions

Repairing disk permissions became obsolete with OS X El Capitan, which protects file system permissions automatically. If you still use OS X Yosemite or older, please continue reading.

Repairing disk permissions is something you should be doing from time to time, even if you’re not experiencing any issues with your Mac.

To do so, open Disk Utility (depending on the version of OS X you’ll find it in Launchpad, or you can always press Command + Space and type Disk Utility to launch it via Spotlight), select your primary hard drive (i.e. Macintosh HD) and click on “Repair Disk Permissions.”

Mac First Aid - How to fix common Mac problems
Disk Utility – Repair Permissions on older versions of OS X

6. Verify And Repair Disk

You can verify the integrity of your disk and its file system in Disk Utility. In newer versions of macOS, Apple calls that feature “First Aid”.

Disk Utility - macOS 10.15 Catalina
Disk Utility – macOS 10.15 Catalina

In most cases, it should not find anything wrong, but if it does, you have to repair it. To do so, you have to boot into the so-called Recovery Mode. To boot into the Recovery Mode, reboot your Mac and hold down the Command + R keys until the Apple logo appears.

Once in the recovery console go into Disk Utility, select the primary hard drive of your computer and click on Repair Disk or First Aid, depending on your version of macOS/OS X.

To learn more about using Disk Utility to verify or repair disks, check out this article. You can also learn more about macOS Recovery here.

7. Reset Safari And Clear Caches

Note: The option to reset Safari doesn’t exist anymore on newer versions of macOS.

To reset Safari and clear all its caches, start Safari and click on Safari (upper left corner of your screen) and select “Reset Safari…“. I’m using Safari 6, so on an older version, you may have to go to Preferences to delete all caches.

Mac First Aid - How to fix common Mac problems
Reset Safari

Depending on if you have a separate password manager (like 1Password), you may want to uncheck “Remove saved names and passwords” or make a backup copy of your passwords before clearing everything out.

Safari - Clear History
Safari – Clear History

On newer versions of macOS, you can still delete all Safari caches, by going to Safari > Clear History. Alternatively, you can remove website data from individual web pages via Safari > Preferences > Privacy > Manage Website Data.

8. Delete Cache Folders

Your Mac and most applications make heavy use of caching, but sometimes that cache can become corrupted and cause all kinds of weird issues. To clear your caches open Finder, press Command + Shift + g and type in ~/Library/Caches.

Alternatively, you can just navigate to your home folder (~) and then into the Library sub-folder. Starting with OS X 10.7 (Lion) Apple decided however to hide the Library folder, so the keyboard shortcut (Command + Shift + g), which corresponds to the following Finder menu: Go > Go to Folder… maybe the quicker route.

Finder - Caches Folder
Finder – Caches Folder

Inside of Library, you’ll see a Caches folder. Step into that folder and drag its contents to the trash (Command + Shift + Delete). Make sure you don’t delete the contents of the Library folder but only the content of the Caches folder.

Repeat the same steps with the following Caches folders:

  • /Library/Caches
  • /System/Library/Caches

For the two Caches folders above, macOS will ask for permission by requiring you to enter your user password. Once the contents of all three Caches folders have been dragged to the Trash, restart your Mac and only then empty the trash.

9. Update to the Latest Version Of macOS

With every new release of macOS, Apple fixes bugs and issues. If you experience problems with an older version of OS X or macOS, chances are, Apple may have fixed the problem in a newer release. As a result, it is worth to consider upgrading to the latest version via the App Store. If you are brave, you can also sign up for Apple’s Beta Software Program.

10. Create A New User Account

In rare cases, problems are associated with your user profile, and the best fix is to create a new user account. This is obviously an invasive step as you may lose settings and preferences. So I consider this almost the last resort. It is worth noting, however, that I often use this technique to confirm if a problem is related to my user account or not. If it is not, there is no need to go through the hassle of setting up a new user.

macOS - System Preferences - Add User
macOS – System Preferences – Add User

To create a new user account, open System Preferences and go to Users & Groups. Then click on the lock icon at the bottom of the screen and then on the plus sign. Follow the steps on the screen to create your new account.

11. Reinstall macOS

Reinstalling macOS is probably the most invasive, but sometimes the only solution. Before you consider reinstalling macOS, make sure you have multiple backups of your data. Also, make a note of important configuration settings so that you can restore them after the reinstall.

In some cases, it is possible to restore your user profile from a Time Machine backup, but in other cases, it is better not to do that. The decision depends on whether or not you think your user settings cause the issue or not. To ease the pain, I have documented the steps I usually follow when I reinstall macOS.

The quickest way to reinstall macOS is to boot into Recovery Mode, erase the primary hard drive and then reinstall from Recovery Console. Before you erase your hard drive, I would recommend reinstalling macOS without erasing the disk.

Related: How to reinstall macOS without losing data.

So you reinstall macOS over the existing installation. You can do that as well from within the Recovery Console.

How To Fix Common Mac Problems

If all those steps did not help to resolve your problem, you have to call Apple Support or make an appointment at the Genius Bar at your local Apple Store.

I’d love to hear your opinion, so leave me a comment and let me know if those steps did or didn’t help to resolve your issue!

18 thoughts on “Mac Troubleshooting Guide”

  1. Since the latest software up-date I have experienced a problem on my Mac computer. When I save something on my desktop, for example, “Oaknoll Retirement Residence”: I see “Oaknoll-retirement-residence-webarchive.”
    But when I click on that, I get the message ““oaknoll-retirement-residence.webarchive” cannot be opened because it is from an unidentified developer.”
    That is the case now for anything I save on my desktop.
    I can get around the problem by going to System Preferences and clicking on Security & Privacy. I see on that page,”oaknoll-re…webarchive” was blocked from use because it is not from an identified developer.“
    There is then the click-on option, “Open Anyway”. When I click on that I get “macOS cannot verify the developer of “oaknoll-retirement-residence.webarchive”. Are you sure you want to open it?
    “By opening this app, you will be overriding system security which can expose your computer and personal information to malware that may harm your Mac or compromise your privacy.”
    If I ignore that advice and click on Open, I do get the Oaknoll Retirement Residence website.
    Can you help with this problem? I would like to be able to recover anything I save on my desktop without having to go through System Preference, Security & Privacy, etc.

  2. Dear Michael;
    Thank you for being available to help with MAC matters and for this handy guide.
    After reinstalling my hard drive and slowly restoring files, it appears my problem is in documents. The problem is that my screen goes black unexpectedly in email, safari and NETFLIX. A reboot might give me a few moments to close properly and complete a quick email before going black again. An over night rest usually gives me an hour of use the next day before the black(like going to sleep but system shuts down completely) starts up again. How do I figure out what is causing this problem in documents. Applications reloaded & system stayed awake. Documents reloaded and screen went black, system shut down and had to be rebooted to close properly.
    Where do I start to fix documents issues?
    With gratitude 🙏 Dawn

  3. A HUGE thank you, Michael. I could not figure out why everything was so SLOW (and for no apparent reason). Reset PRAM and NVRAM did the trick! Thank you again!

  4. Good day Sir
    My Name is joseph Babila,
    I am from Cameroon the north west region.
    just to say thanks for the above information on how to solve the continues restart on mackbook pro.
    I finally succeed to put up the system register and could browse with it
    but it look like the hard drive is having a problem.
    it suddenly go off after some time of usage and goes to blank screen.
    looking forward to look for a new hard drive to reinstall the system
    Thanks and have a nice day

  5. Your advice seems very good. I am an elderly woman with a Mini Mac. My computer is older – late 2014. I am using Chrome MacOS Mojave version 1014.6.
    I guess Google was keeping a copy on my Mac of every e-mail I received. I did delete my copy of the e-mails but not Google’s copy. I ran out of space and have deleted
    over 160,000 e-mails because I did not want to pay for more space.
    Now my e-mails are going into GMail’s Inbox, junk folder and several other categories but will not go into my regular mail folder. I don’t understand all of your terminology, but I wonder if you know how I can fix this.
    Any help would be very much appreciated.
    [email protected]

  6. still i have a problem to install jdk,maven,homebrew and other. i tried every step,but couldn’t find the problem.

  7. Great article. I faced wifi connecting problem with my mac to wifi. I took help from Dell printer Support. If you facing this problem then can take help of them.

  8. Thanks for updating such informational post it seems as though writer has listen my problem. This was very useful and guided me in best manner to find solution for my Macbook.

  9. Thanks for sharing these fixes for common mac problems. My data cache folder seems to have gotten corrupted recently. I had no idea that you could safely clear it using Command + Shift + g. I’ll have to try this out and see if it deleted and restored.

  10. What I’m worried is the SSD. SSD dies without warning, unlike HDD. The SSD of my Mac mini server main HD died suddenly so I even not using SSD now on my server. Besides time machine, I have a carbon copy cloner cloning my Macbook Pro regularly.

  11. Thanks for the excellent advice. I’ll add that I’ve found that Apple has built in some self-healing features. Twice, when I’ve had problems starting up, I’ve simply restarted several times. At that point, macOS seems to realize that there are issues. Some it may fix from files on disk, but I get the impression that, if the Internet is available, it’ll download what it need to fix the problem.

    Quite handy!


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