How to Fix Boot Loop on a Mac

Boot Loop is a common issue on Macs, and can be a real headache to solve.

If you're finding that your Mac is constantly loading into a boot loop, there are a few things you can do to try and fix the issue.

So, how do you fix boot loop on a Mac?

In this article, we'll discuss some of the most common causes of boot loop on a Mac, and how to fix them.

Hopefully, this will help get your Mac back up and running in no time.

I’ll talk about hardware issues and software issues that can cause your Mac to get stuck in a boot loop as well as a section on how you can prevent your Mac from constantly rebooting.

Remove any Peripheral Hardware Components
Update the Firmware on the Mac
Find and Update Corrupted Software
Repair your Mac’s Disk Permissions
Disable Startup Applications
Reinstall MacOS to Fix the Problem

Let’s Begin!

What is the boot process of a Mac?

The boot process of any Mac is fairly simple. Simply pressing the power button will start the system, but what exactly runs in the background as the Mac loads?

Based on my findings, here are a couple of things I was able to find out about the Mac boot up process.

The first thing to boot up is the hardware and firmware that is installed on the Mac.
Next, the firmware begins to run the power--on-self-test and then tests the Mac’s processor, memory and peripheral attachments.
Finally, once everything has been checked in the boot up process, the Mac will indicate a successful boot by enabling the display and sound.

What causes the Mac to constantly reboot?

While a number of reasons can cause your Mac to constantly reboot, the main causes are

Issues with applications
Hardware or peripheral devices that are not compatible with the Mac
There’s not enough RAM or Storage space on the Mac
Drivers are outdated and need to be updated.

Here are some quick fixes depending on what’s causing the Mac to enter boot loop.

Problem #1 -- Hardware Issues

Most of the time, newly installed hardware components can be the cause of your Mac entering boot loop.

This can vary from a new RAM being installed to a new hard drive or printer as well.

However, it’s relatively easy to fix, as I'll show you below.

Solution

Follow these steps to prevent your Mac from rebooting continuously.

Shut down your Mac
- Click on the Apple icon from the status menu and tap on Shut Down
Now, disconnect any new hardware you installed prior to the problem.
- Make sure that your display, keyboard and mouse are still connected to the Mac

Restart your Mac and then add one device at a time to determine where the problem lies
Now you will know whether the printer or your new RAM is the cause of the boot loop issue and changing the component will rectify the problem.

Problem #2 -- Software Issues

When you install a new software that’s either not compatible with your Mac or if it takes up too much storage space on your Mac then there are chances that your computer will enter the boot loop cycle because it will not be able to support the new software.

Luckily, there are a number of ways you can fix software issues that cause a Mac to boot loop.

Let’s take a look at some of the most common reasons and their fixes.

Solution #1 -- Update the Firmware on the Mac

Start by holding down the Shift button on the keyboard and reboot the Mac into Safe Mode
- Start Menu > Shift key + Restart

Now backup your data onto an external hard drive while in Safe Mode

Proceed to check for software updates on your Mac and then update them using the Software Update tool.

If the problem persists, uninstall and reinstall the software. If this also doesn’t work then remove the software altogether from your Mac.

Solution #2 -- Find and Update Corrupted Software

The second method is to locate the software that’s causing the problem and have it updated to the latest version.

Update the software on your Mac and then reboot the system
For those who are unable to update or reinstall the application, delete the app from the Mac
Proceed to reinstall the software on your Mac

If you have received a Kernel Panic error message then the issue might not be due to an application, but it could be a fault of the drivers or other permissions on the Mac.

Solution #3 -- Repair your Mac’s Disk Permissions

A quick troubleshooting trick to resolve the boot loop on Mac is to repair the disk permissions.

To do this on older Macs running Yosemite

Press Command + R to Restart your Mac

Once the Mac reboots, launch Disk Utility from the macOS Utilities tool
Select the Disk from the left panel and then tap on First Aid at the top of the screen

Now tap on Repair Disk Permission.

If you’re running macOS Sierra or later

Run the CleanMyMac X application
Choose Advanced Maintenance Module
Proceed to Repair the Disk Permissions.

Solution #4 -- Disable Startup Applications

If your Mac has entered boot loop because of the number of startup applications you have running, closing and disabling them should resolve the issue.

To do this,

Start by selecting the Apple Menu icon
Choose System Preferences and then tap on Users and Groups

Select your Username from the Menu and then click on the Login Items tab
Click on the startup application you want to disable and then tap on “_”
Restart the Mac

You can replicate this process until you’ve closed all the unnecessary startup applications that are running on your Mac.

In order to figure out which application is causing the boot loop issue, try adding back one app at a time and restart the Mac in between applications.

When the Mac enters boot loop, you will know which app is the cause of it and then you can decide what you want to have done, either keep the app or uninstall it permanently.

Solution #5 -- Reinstall MacOS to Fix the Problem

The final option to solve the boot loop problem on a Mac is to reinstall the complete OS.

Wiping out the operating system from the Mac and installing a fresh copy will eliminate any bugs or issues that may cause your Mac to boot loop.

Here’s how you can reinstall MacOS to fix a boot loop problem

Start by restarting your Mac and then as the system boots, press and hold Command key + R

When the Disk Utility appears, click on Reinstall MacOS

This will wipe out all the data on your Mac and install a new copy of MacOS for you. Doing this will remove any software problems and you will be presented with a clean copy of MacOS.

How to Prevent a Mac from Entering Boot Loop?

It’s always a good idea to keep your Mac clean so that it doesn’t enter boot loop.

To do this, here are three tips you can try on your own to prevent a Mac from entering boot loop mode.

Tip #1 -- Make Sure your Mac OS is Up to Date

If the Mac is not updated to the latest or current version then you will definitely face issues with the OS and system applications.

The best way to keep your Mac healthy is to update the firmware regularly. Sometimes, there may be a bug in an older version of macOS and Apple will release an update to fix the issue.

Not installing the update will result in more problems that can occur at any time.

Tip #2 -- Check the Software Compatibility before Installing any Apps on your Mac

There’s a saying, prevention is better than a cure. The same applies to software and MacOS.

If you do not want to face any problem with background processes or getting stuck in a boot loop, it’s best that you verify first if the software is compatible with your version of MacOS.

One thing you can do is check online forums for information about the software you’re going to install.

It’s also good to go through the installation details of the application before running it on your Mac.

Tip #3 -- Check the Hardware Compatibility of your Mac

Similar to how you can prevent boot loop caused by software, you can prevent your Mac from entering a boot loop by installing or connecting the right hardware components.

Mac does not play well with many third-party devices, so ensure the component you’re connecting to your Mac is legitimate and is supported by MacOS.

You can also check public forums such as Reddit to find out if anyone has faced issues with particular hardware components or if the device you’re planning to install is safe to use with your Mac.

Takeaway

Always remember, if you’re dealing with boot loop issues on your Mac, you don’t have to be a certified technician or IT expert to fix the laptop.

Since most of the time, boot loop problems are caused by either software or hardware issues, make sure you determine what’s causing the problem and use one of the quick fixes in this article to troubleshoot the issue.

You can also run the built-in troubleshooter to find out what’s causing the Mac to boot non-stop.

I hope this guide helped you get out of an infinite boot loop on your Mac.

Until next time!

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