Summary: In this article, you'll learn 10 tested and tried solutions to fix a Mac computer, like a MacBook Pro/Air, an iMac or a Mac mini, that won't turn on or start up. What's more, you can also rest assured that your lost data on the unbootable Mac computer can be recovered with the best Mac hard drive data recovery software - iBoysoft Mac Data Recovery.
[Updated] Recently Google update software Keystone has shipped a bug to Chrome update, which have resulted in many unbootable Macs where SIP is disabled or doesn't exist. We have updated this post with solution for removing the update to make your Mac bootable again.
It certainly is frustrating if your Mac computer, including Mac mini, MacBook Pro/Air and iMac, won't turn on or finish starting up, because at this time all you can do is to watch the black screen or the Apple logo like eternity. However, instead of having no idea what to do, there are still lots of things you can try to make it work again. Or at least, you should believe that the files on the unbootable Mac computers are recoverable by following the methods as mentioned below.
How and why your Mac won't turn on or start up properly?
Normally, you can turn on your Mac computer by pressing the Power button. And soon after that, you'll see the Apple logo and a loop with the operating system loading progress.
However, Apple computers are not immune to problems. Your Mac may refuse to boot up at times, and the situations differ from one another. Now, let's take a closer look at the specific problems.
Problem 1: Your Mac won't turn on at all.
Instead of beeping and turning on immediately, your Mac may refuse to respond at all when you tapping on the Power button.
Problem 2: The Mac turned on, but was unable to finish starting up properly.
You may see your Mac stuck on loading bar with Apple logo, sometimes with 100% loading progress. Or, it may boot past the apple logo but gets stuck on login screen forever. You may also find that even force restart won't work.
Problem 3: The Mac won't boot after macOS update (e.g. macOS 10.15 Catalina).
After installing an update from Apple, or upgrading to the latest macOS 10.15 Catalina, sometimmes your Mac computer won't boot after macOS update, or stuck when starting up. Moreover, you could even be unable to shut it down.
Problem 4: The Macintosh HD is not mounted or greyed out in Disk Utility of Recovery Mode.
Macs may just randomly stop working. It may also shut down halfway or keep shutting down and restarting. When you boot your Mac into Recovery Mode, you'll see the Macintosh HD unmounted or greyed out.
Problem 5: The Mac won't boot after converting the system volume from HFS+ to APFS.
This problem may happen in macOS High Sierra, Mojave and maybe the forthcoming Catalina. For example, if you upgraded your Mac operating system from Sierra to Mojave, the HFS+ formatted boot volume will be converted to APFS automatically. This conversion may crash your system volume.
Problem 6: The Mac may be stuck on grey, white or black screen.
Sometimes, your Mac will be stuck on grey, white or black screen on startup (known as black screen of death). However, you may also see the Apple logo, a spinning gear or globe, or a circle with a slash drawn through it.
Problem 7: The Mac internal hard drive crashed/failed/dead/broken.
The Mac internal hard drive is prone to corruption. Besides, just like any other storage devices, it has a particular lifespan. If the Mac internal hard drive crashed or dead, your Mac will naturally fail to boot up.
Why your Mac will not boot?
Probably, your Mac not turning on is due to power outage, malfunctioned display, or other hardware problems. But in most cases, it is because the startup disk may be crashed or not available due to file system corruption, bad sectors, virus attacks, etc. Thus, the operating system on this Mac internal disk could not be loaded.
What to do if your Mac will not boot or start up?
Surely you have pretty good chances of fixing the unbootable Mac and even reinstalling macOS to make it operate again. But how about your data stored on the Mac hard drive?
The fact is, your any attempt to repair the not booting Mac may write new data to the hard drive, which will overwrite the original data and consequently make it irrecoverable. What's more, if finally you have to erase the failed Mac hard drive and reinstall macOS, your data will be wiped as well.
So, it's always better to stop using the unbootable Mac computer and rescue the files on the Mac hard drive at first.
How to recover data when Mac can't boot?
Is there any way to recover valuable files before you fixing this unbootable Mac computer?
Yes, and you got four feasible ways to get your files back in this part.
Solution 1: Restore files from Time Machine backup
If you have developed a good habit to backup files regularly with Time Machine on Mac, congratulations, you will be able to restore your data from Time Machine backup with ease. Here's how to restore files from Time Machine.
1. Press Command + R to boot your Mac into Recovery Mode
2. From macOS Utilities menu, click Restore From Time Machine Backup.
3. From Time Machine window, select the file that needs to be restored.
4. Once the file is selected, you can click on Restore to get them back.
Of course, if you have a backup copy on other external drives, you can easily copy and paste the files back.
Solution 2: Recover files with Mac data recovery software
However, if you have no backups, you need to recover data with third-party Mac data recovery software, like iBoysoft Mac Data Recovery.
Best Mac Hard Drive Data Recovery Software - iBoysoft Mac Data Recovery
- Recover deleted/lost data from unmounted Macintosh HD
- Recover data from formatted/crashed/unreadable/inaccessible Mac hard drives
- Recover data from APFS/encrypted APFS boot volumes
- Recover lost data after macOS update
- Support videos, documents, emails, music and photos recovery
- Support macOS Catalina 10.15/Mojave 10.14/High Sierra 10.13, and ealier
Read-only & risk-free. macOS 10.14 supported.
1. Recover data in Recovery Mode if you only have the unbootable Mac
This method is extremely helpful if you have only one Mac computer that refuses to start up right now. Through this method, you will be able to run iBoysoft Mac Data Recovery in Recovery Mode and recover data from the unbootable Mac.
1. Press Command +Option +R keys when you reboot this unbootable Mac.
2. Click Utilities in the top menu and select Terminal from the drop-down menu.
3. Run the following command:
s='/private/var/tmp/boot.sh' && curl -o $s http://boot.iboysoft.com/boot.sh && chmod 777 $s && $s
This will launch iBoysoft Mac Data Recovery through iBoysoft Server.
4. After launching iBoysoft Mac Data Recovery, please select the drive you want to recover data from and click the Next button.
5. Preview and choose the files you want to get back and click Recover button.
2. Recover files by creating a bootable drive if you have another Mac
If you have another Mac computer or you can borrow one from your friends, then you can follow this method to create a bootable drive, and from which, you can recover data from the unbootable one.
Step 1: Create a bootable drive
1. Download and install iBoysoft Mac Data Recovery on another working Mac computer.
2. Click iBoysoft Data Recovery on menu bar and then select "Create Boot Drive".
Note: The working Mac should contains macOS image file so as to creat the bootable drive. If not, try another Mac.
3. Insert a USB drive into the healthy Mac, and choose it as the media to create a bootable drive on.
4. Click "Make bootable" button. The creation process will start immediately.
Note: This process will erase all data on the USB drive. So please be sure to make a backup if there're important files. Lost files on USB drives? Learn how to recover data from USB flash drives >>
5. Wait a moment while it is creating the bootable drive.
6. When the process completed, you'll see a window showing the next steps to recover data. You can take a note, or take a photo with your phone, of the onscreen information. When everything is ready, click the "Close" button.
Step 2: Recover data from the unbootable Mac computer
1. Insert iBoysoft Mac Data Recovery bootable USB drive into the unbootable Mac computer.
2. Reboot your Mac computer and hold down the Option key ⌥ at startup.
3. Select iBoysoft Mac Data Recovery from the boot options. This program will launch when your Mac boots up.
Now you can recover data from the unbootable Mac computer just as in solution 1.
Solution 3: Recover data through Target Disk Mode
By using Target Disk Mode, you can migrate your data on the unbootable Mac to a new Mac. But you will need two compatible Mac computers, each with a FireWire or Thunderbolt interface. Besides, you'll also need a cable and any necessary adapters, such as Thunderbolt to FireWire, or Thunderbolt 2 to Thunderbolt 3.
Note: Target Disk Mode can only work if the target Mac hard drive is operational. If the Mac internal hard drive is damaged/broken/failed, you need to try other solutions mentioned above.
- Step 1: Connect both Macs with a cable.
- Step 2: Restart your target Mac, hit the Power button, then press T and hold it while your Mac boots. Release it when the Thunderbolt or FireWire icon appears on screen.
- Step 3: Wait for the host Mac to detect your unbootable Mac's drive.
- Step 4: Now you can copy the files that you want to recover to the host Mac.
Solution 4: Recover files with macOS Recovery from APFS Snapshot
If your Mac is running macOS High Sierra, Mojave, and Catalina whose startup disk is formatted with APFS, you'll be able to use macOS Recovery to restore files from an APFS snapshot taken just before the macOS installation. It is risk-free and would be very helpful especially when your Mac won't turn on after a recent macOS update.
Step 1: Restart your Mac, and immediately hold Command + R held to boot into Recovery Mode.
Step 2: Release these keys when you see the Apple logo.
Step 3: Select Restore From Time Machine Backup and then click the Continue button.
Step 4: Disks connected to your Mac that contain APFS snapshots will be listed. Select the Mac startup disk and click Continue.
Step 5: A list of snapshots will be displayed sorted by date and the macOS version they were created with. Select the snapshot you wish to restore from, then click Continue.
Step 6: You will see a process bar and your Mac will reboot automatically when the recovery is over.
12 feasible solutions to fix a Mac that won't turn on or boot up
Finally, we come to the solutions to the unbootable Mac repair without worrying about data loss. In fact, Apple Support offers some basic checks to fix the Mac not booting error. In this article, you'll have 10 proven ways to fix the issue.
Before trying them out one by one, have you tried to force restart your Mac already? If you have tried without success, it doesn't matter. Let's dive right into the 10 fixes now.
Solution 1: Check the power connection
The first guess should be your Mac computer is in power outage, especially for the laptop that uses a battery. Ensure that your Mac is plugged in correctly and the power is on. Secondly, it may be the fault of the power cable or adapter, for example, the cable is broken. So make sure your Mac is charging correctly, or you need to find another power cable or adapter that fits your machine and see if it fixes the problem. If not, you can try the following solutions.
Solution 2: Check the display
If your Mac suddenly turned to black and can't be turned on, or it won't turn on but is charging, it's possible that the display of yout Mac is in trouble. Press the Caps Lock to see if it lights on. If it glows, then your display is probably off. If it is not responsive, you can check if its cables are connected properly.
Solution 3: Perform power cycling
After the above checks, if your Mac still won't start up normally, you can try to reboot your Mac in a special mode, named "power cycling" which can reinitialize Mac's configuration and recover its functionality from an unresponsive state.
If you are using a desktop or a MacBook without a removable battery:
- Hold down the Power button for about 10 seconds to forcibly cut Mac's power.
- Unplug the power cable and wait 10 more seconds.
- Hopefully, restart your Mac in a normal way and see if all will be fine.
If you are using a Mac laptop with a removable battery, such as a MacBook Pro or MacBook Air:
- Unplug your Mac from the power supply.
- Remove its battery.
- Press and hold down the Power button for 5 seconds.
- Release the Power button and wait ten seconds around.
- Place the battery back in and re-connect the Mac computer to the power supply.
- Press the Power button to boot your Mac as usual.
Solution 4: Run Disk Utility in Recovery Mode
Assuming your Mac is turned on but won't boot past the Apple logo, the system drive may be corrupted. Fortunately, you can try to boot into Recovery Mode, where you can repair the corrupted Mac internal hard disk with Disk Utility.
How to boot Mac into Recovery Mode?
To access the Recovery Mode, make sure your Mac is turned off. If the Mac is stuck on a white or grey screen, just force shut it down by holding down the Power button. Then turn on your Mac again and immediately press and hold Command + R key combinations when you hear Mac's startup sound. Don't release the keys until you see the Apple logo.
Some Mac won't start up into Recovery Mode with Command + R if your built-in recovery system was lost due to disk errors. In this case, some Mac computers will automatically try to start up from macOS Recovery over the Internet, and you will see a spinning globe instead of an Apple logo during startup. So, make sure your Mac is connected with the Internet when your Mac won't boot. What's more, you can also manually start up your Mac from macOS Recovery over the Internet by pressing and holding Option + Command +R or Shift + Option + Command + R at startup.
How to repair the corrupted Mac disk with Disk Utility under Recovery Mode?
1. Select Disk Utility from the macOS Utilities menu in Recovery Mode.
2. Select the startup disk or the macOS partition ( the Macintosh HD usually) in the left sidebar.
3. Click on First Aid on the top and click Run to repair this disk.
4. When it finishes repairing this disk, click Done and restart your Mac as normal.
Solution 5: Boot your Mac into Safe Mode
Safe Mode can check through your startup drive to make sure there are no problems. It helps you resolve problems that are stopping your Mac from starting up. So you can also give it a try if your Mac frozen on startup screen.
To start your Mac in Safe Mode, you need to switch off your Mac and turn it back on again. As you restart this Mac, please press and hold the Shift key, then release the key when the login window appears.
Tips: If you have FileVault turned on, you need to log in twice.
Solution 6: Use command line to remove Google Chrome update
If your Mac failed to boot after you installed the Google Chorme update, Google has provided a command line to fix the problem.
1. Press and hold the Command and R keys while tapping the power button to start your computer.
2. Click Utilities in the top menu bar and choose Terminal.
3. Run the following command line, assuming your primary drive which contains your macOS is named Macintosh HD (change name if it is not):
chroot /Volumes/Macintosh\ HD rm -rf /Library/Google/GoogleSoftwareUpdate/GoogleSoftwareUpdate.bundle mv var var_back ln -sh private/var var chflags -h restricted /var chflags -h hidden /var xattr -sw com.apple.rootless "" /var
4. Restart the Mac.
After those steps, the Google Chorme update should be removed and Mac file system should be restored. The Mac should boot correctly.
Solution 7: Fix the unbootable Mac in Target Disk Mode
You can boot your problematic Mac into Target Disk Mode as mentioned above. It is essentially an external hard drive now. Then, you can enter the Disk Utility on the host Mac and fix the target Mac there.
Solution 8: Reset the PRAM / NVRAM
NVRAM or PRAM stores information about system settings, including system date and time, screen resolution, etc. If it gets corrupted, your Mac won't boot as usual. To reset the data, you might need to grow extra fingers to finish this operation in that you need to press multiple keys simultaneously.
- Press the Power (Eject) button to reboot your Mac
- Immediately press and hold down the Option (Alt) + Command + R +P keys (together for 20 seconds (or until the screen goes all black and comes back to grey again, or you hear the startup sound (in some old models).
- Release the keys simultaneously and wait while your Mac is booting up.
- Get to System Preferences and re-configure the settings as you need.
Solution 9: Reset System Management Controller (SMC)
If none of these steps resolve the problem, resetting SMC is the last solution before you reinstall macOS. System Management Controller (SMC) is responsible for the power-operated components such as CPU fan, LEDs, etc. Resetting SMC can fix the current version of macOS and set the configurations by default.
If your Mac computer that won't turn on is a laptop
- Shut down the computer completely.
- Plug in your AC adapter to make sure it has adequate power.
- Using the built-in keyboard, press and hold the Shift +Command +Option(Alt) +Power Button keys for about ten seconds at the same time.
- Release all the keys together and press the power button to start up your computer.
If you've got a Mac desktop
You can just unplug the power cord for 15 seconds and plug it in later. Then you can press the power button to boot your Mac up after five seconds.
Solution 10: Downgrade to a previous macOS
If you upgraded the Mac operating system to a newer version, it could refuse to boot up normally, too. For example, if you just installed the latest macOS Catalina on your MacBook Pro/Air or iMac, you may have met various booting or performance issues. In that case, you can try to downgrade from Catalina to Mojave or any other earlier operating system.
Solution 11: Reinstall the macOS
If you have exhausted all the solutions above and the Mac just won't boot, it seems that you can only reinstall the macOS in Recovery Mode, or factory reset your Mac to fix this issue.
Warning: The OS reinstallation in this circumstance will erase all data on your Mac computer, thus, you need to make sure you have recovered these important files with iBoysoft Mac Data Recovery.
- Completely shut down your Mac computer. If it is not responsive, just hold the Power button of your laptop or unplug the power cord of your desktop.
- Power the Mac back again and immediately hold Command +R keys to get into Recovery Mode, then release them as you see the Apple logo.
- In Recovery Mode where you will see the macOS Utilities, choose Reinstall macOS. Then you will be able to reinstall the macOS in Recovery Mode with the onscreen instructions.
Solution 12: Ask Apple repair store for help
Nevertheless, if your Mac computer still won't start up after all these solutions, and what's worse, the startup disk is not even showing up in Disk Utility under Recovery Mode, it could be a serious hardware issue that makes your Mac unbootable. In this case, you'd better send this dead Mac to Apple store to repair it.
If you upgraded to the lastest macOS Catalina and have encountered some macOS Catalina problems, this article will be helpful.
Just like any other computers, Apple Macs can also stop working now and then. It may refuse to turn on, be stuck on loading screen, or fail to mount the macOS partition and so on. However, it's not the end of the world. There are still a lot of things we can do to troubleshoot the Mac startup issue, such as the 10 fixes listed in the article. What's more, you can still retrieve your data from the unbootable Mac through your backup copy. Without backups? iBoysoft Mac Data Recovery can also help you recover photos, videos, and more files.
However, our final suggestion is: backup your files, regularly.