If your Mac is frozen and unresponsive, a forced restart should help. To do this, press and hold the power button until the Mac screen turns off, and then turn on the computer as usual.

Attention! With this shutdown, unsaved data in applications will most likely be lost.

2. Removing removable media

Eject (⏏) or F12

During a crash of a Mac with an optical drive and a disc inside, the system may fail to boot from it and freeze. Press the ⏏ (Eject) or F12 key on your keyboard, or press and hold the mouse or trackpad button to eject the media.

3. Selecting a boot disk

If your Mac has multiple disks installed and the system cannot boot from the default disk, you can open the bootable disks selection dialog and select the desired media manually. To do this, press and hold the ⌥ (Option) key immediately after turning on the computer.

4. Boot from CD or DVD

Likewise, you can instruct your Mac to boot from disk from the built-in or external optical drive. In this case, press and hold the C key on the keyboard.

5. Download from server

⌥N (Option + N)

Once you have a NetBoot server on your local computer that has a bootable system image, you can try to start the Mac using it. To do this, press and hold the ⌥N (Option + N) key combination.

This boot method does not work on computers with an Apple T2 processor.

6. Run in Target Disk Mode

If your Mac doesn't want to start up, you can put it in Target Disk Mode and copy important files by connecting it to another computer using a FireWire, Thunderbolt, or USB-C cable. To start in this mode, press and hold the T key when turning on.

7. Run in verbose mode

⌘V (Command + V)

By default, macOS does not display a detailed startup log, showing only a loading bar. If problems arise, you can enable a verbose log to help you understand at what stage of the download the error occurs. To do this, when turned on, press the shortcut ⌘V (Command + V).

8. Start in Safe Mode

When your Mac won't boot normally, it's worth trying to launch Safe Mode. It checks the disk and turns on only the basic components of the system, which allows you to determine which named programs or services are causing errors. Press and hold the ⇧ (Shift) key to boot to Safe Mode.

9. Single user mode

⌘S (Command + S)

This mode starts the system in an even more stripped down version - only the command line is available in it. Nevertheless, with its help, specialists will be able to diagnose and correct errors if any. To start in single-user mode, press the keyboard shortcut ⌘S (Command + S).

10. Run diagnostics

macOS has built-in hardware diagnostic software to help diagnose hardware problems. Press and hold D to start diagnostics.

11. Run network diagnostics

⌥D (Option + D)

If the boot disk is damaged, then the diagnostic test will not work. In such cases, network diagnostics can help, allowing you to run the test over the Internet. To do this, press the combination ⌥D (Option + D)

12. Recovery mode

⌘R (Command + R)

When booted in recovery mode, you can access Disk Utility, reinstall macOS, and restore data from a created backup. Press and hold ⌘R (Command + R) to enter recovery mode.

If you have a firmware password set on your Mac, you will need to enter it.

13. Network Recovery Mode

⌥⌘R (Option + Command + R)

A mode similar to the previous one, which, in the presence of the Internet, allows you to reinstall macOS by downloading the system distribution kit directly from Apple servers. To use it, press ⌥⌘R (Option + Command + R).

14. Reset NVRAM or PRAM

⌥⌘PR (Option + Command + P + R)

If you have problems with the display, speakers, cooling fans, or other Mac components, you can try to resolve them by resetting NVRAM or PRAM. To do this, press and hold the ⌥⌘PR keys (Option + Command + P + R) at startup.

If you have a firmware password set on your Mac, this method will not work.

15. Reset SMC

A more drastic reset is to revert to the default System Management Controller (SMC) settings. It is applied if the previous method did not help. Resetting the SMC is performed differently depending on the Mac model.

On stationary computers shut down your Mac, unplug the power cord, and wait 15 seconds. Then reconnect the cable, wait five seconds and press the power button to turn it on.

On laptops with a removable battery you must turn off your Mac, remove the battery, and then press and hold the power button for five seconds. After that, you need to install the battery and press the button to turn it on.

On laptops with a non-removable battery shut down your Mac and hold down Shift + Command + Option with the power button for ten seconds. After that, release all keys and press the power button to turn on.

On a MacBook Pro with Touch ID, the sensor button is also the power button.

In rare cases, after installing a system update or other software problems, the apple computer may freeze at boot with a "white screen" that does not have a logo or a loading indicator. In this article, we will try to give some tips that can help in this case.

Reboot to Safe Mode

One of the easiest ways is to reboot into Safe Mode. To do this, hold down the Shift key while booting the computer. If after starting up your Mac in Safe Mode, you can try starting your computer without pressing any keys.

Reset NVRAM

To reset NVRAM on Mac, you need to:

1. Shut down your Mac.
2. Turn on the computer.
3. Immediately after the power-on signal, hold down the Command + Option + P + R key combination.
4. Hold them down until the computer restarts and the startup signal sounds a second time.
5. Release the keys.

Reset SMC

For laptops:

1. Shut down Mac
2. Disconnect the MagSafe or USB-C power adapter.
3. Press Shift-Control-Option while pressing the Power button.
4. Hold them for 10 seconds.
5. Release all keys.
6. Connect the power adapter.
7. Turn on Mac.

For desktops:

1. Turn off computer.
2. Disconnect the power cord.
3. Wait 15 seconds.
4. Reconnect the power cord.
5. Wait 5 seconds and press the power button to turn on your Mac.

Reboot and repair disk

If you experience a white screen, you can try to repair the boot disk using Disk Utility. For this you need:

1. Restart your Mac while holding down Ctrl + R keys to boot into recovery mode.
2. In the list that appears, select the Disk Utility item.
3. Select the drive to be repaired.
4. Click on the First Aid button.

Disk Utility can fix basic problems. However, if she reports that a disk failure is about to occur, it is best to back up your data, back up your data and replace the disk.

Reinstall macOS

If other methods do not help, then you can try to solve the problem by reinstalling the operating system. Details of this process on the Apple technical support site.

Despite the high degree of reliability and performance, different models of MacBooks may have difficulties in loading the system. What to do if MacBook won't boot?

Causes

Three groups of sources can be distinguished, due to which the device may not start:

1. Component problems. This may be a breakdown or a malfunction of the hard disk, RAM, etc.
2. Mac OS malfunctions.
3. Incorrect connection of third-party devices.

Troubleshooting methods

If your MacBook freezes while starting up, you need to do the following one by one:

• boot in safe mode;
• use disk utility;
• make copies of files through the external disk mode and reinstall the OS.

Starting in Safe Mode is useful if mac OS won't boot. The procedure is as follows:

1. Turn off the problem device by pressing and holding Power.
2. Restart the MacBook while holding down the shift key.

1. It may take some time to turn on, so it is worth waiting a little.
2. An additional feature (verbose mode) is provided to track boot processes. To start it, you need to simultaneously press: shift + command + V. This mod displays detailed information about the loaded objects.

If you start the MacBook in safe mode, we reboot through the top Apple menu.

If the reason for the freezes is the hard drive, you can solve the complexity using the disk utility.

1. Turn off the MacBook. If a freeze occurs with a functioning disk, and a white screen is displayed on the matrix, you need to forcibly interrupt the operation of the device by pressing and holding the Power button for a few seconds.
2. Launch and open recovery mode. Press the power button while holding down the command + R keys.

1. The OS X Utilities window will appear on the screen. From the four options in the window, select the disk utility block.

1. Select the required disk line in the window.
2. We start the process by clicking on Verify Disk.

1. If problems with the disk are identified, a solution will be offered. To fix the problem, you will need to click on the Repair Disk button.

1. After the completion of the process, another reboot of the device is performed.

If, after performing the above steps, the MacBook still freezes at boot, it is recommended to reinstall the OS, with the preliminary saving of the data. For this, a special mode of the external disk is provided. To activate it and save data, you will need:

• second working MacBook;
• connect active devices to each other via a Thunderbolt cable;
• forcibly turn off a frozen MacBook;
• start a non-bootable device and immediately hold down the T key;
• hold it until the Thunderbolt icon appears.

The service has started. Now, on a properly working device, the Finder displays the hard drive from the second connected device. We transfer all important data from it to a working MacBook. After completing the procedure, safely remove the disk and disconnect the cable.

Moving on to reinstalling the MacBook OS. We carry out the following actions:

1. We start the recovery mode, as it was done in the case of the disk utility.
2. In the window that opens, select the "Reinstall OS X" field.

1. We follow the step-by-step instructions until the procedure is completed.

If, after reinstalling the OS, the MacBook still does not boot, you should contact special services.

Despite the fact that the iMac computer is a reliable device, it is still not perfect, and therefore all kinds of software and system failures are not alien to it. The worst failure, of course, is not the desire to turn on. Fortunately, this kind of behavior of the Apple iMac does not always indicate a serious breakdown. In this article, we'll explain why your iMac won't boot and what you can do yourself to fix the problem in a given situation.

First of all, of course, we should diagnose the situation in order to understand whether we can cope with it on our own or not. And the main point is to determine the nature of the problem - if it is software, that is, it is associated with certain glitches of the system, then it, as a rule, can be eliminated independently. In a situation where the problem is of a hardware nature, there is already the reason for the malfunction of some "iron" component, "and therefore, most likely, service and expensive repairs will be required.

How do you know if the problem is software?

There can be a great variety of system conflicts, due to which the aimak of model A 1224 or any other model does not turn on or load, there can be a great many, however, to exclude the most popular it is enough to do the following steps.

Checking the boot disk

If your iMac turns on but doesn't boot to the final stage, the first thing to do is check to see if the boot disk settings are out of order. To do this, as soon as the device starts to boot, press the Option key and check if the correct disk is being used to boot. The correct boot disk is Macintosh HD.

If you have a Macintosh HD disk installed as a bootable one, but the iMac still does not boot, then we are looking for the problem further - we are trying to activate Safe Mode. To get into this mode, you need to hold down the Shift key when starting the device. If you manage to get into safe mode, we reboot from it and then after it, most likely, the computer will be able to boot normally without problems.

Disconnecting peripherals

All sorts of disks, flash drives and other components connected via a USB interface that are not removed by the user when the iMac is turned off can also cause a system failure. To exclude this reason from the list of possible options "Why didn't the iMac boot?", We disconnect all peripherals that connect to the device via USB (even if there were no conflicts with this equipment before), and also do not forget to remove the disks.

Resetting the settings

Have you taken everything out and turned off and your iMac still won't turn on? Do not be alarmed, all is not lost yet! Click on the boot button again and this time, when starting the system, we hold down the Command + Option + P + R combination, thus we reset the NVRAM settings - this memory area is responsible for saving the set time zone, time and other system parameters, so do not be surprised that after the reset, you will have to configure these iMac settings again.

Resetting the power controller settings

If you're still reading this article, then your iMac still won't boot. Don't worry, we still have a couple of ways to get him to do this. First, we reset the power controller settings, this is done very simply - completely disconnect the computer from the network, wait 15-30 seconds, connect the network cable, wait 5-10 seconds and try to boot the computer.

Start your Mac in command line mode

And finally, the last desperate step, which, unfortunately, often leads to the need to reinstall the system, which means that some of your data may be lost. What needs to be done? When loading the iMac, hold down the Command + S combination, the command line will start, enter the "fsck-fy" command into it - thereby you initiate a file system check that will help eliminate existing software failures (if any, of course). After completing the diagnostics, specify "reboot" in the command line - the PC should start booting.

An important point! If you're not ready to reinstall your iMac, it's best not to take this step.

How do you know if the problem is hardware?

In fact, if all the above measures did not help to solve the problem, then most likely you are faced with a hardware problem. Another argument for the problem with the hardware is a complete refusal to turn on - that is, the download does not even start. However, nevertheless, before taking the device to the service, we recommend contacting Apple support, the chance that its specialists will help you is not so small.

If the support service is powerless, then we go to the service and hope that we will be able to get by, as they say, with little blood. The most "light option" - the power cord is faulty. However, practice shows that more often the reason for loading the iMac lies in problems with the power supply and video card, and sometimes even the hard drive suffers.

Let's summarize

So, if your iMac does not turn on, first of all, with the hope that in your case the problem is of a software nature, we are consistently trying to fix it, guided by our advice. If none of the advice helps, contact Apple Support. In a situation where its specialists are powerless, we carry the computer to the service center and believe that we have not come across a serious breakdown.

If, when you turn on your iMac, you see a white screen and the absence of any traces of the computer booting, then the problem is most likely in the hardware (hardware).

Typically, a white screen on an iMac occurs when an iMac component fails to load the operating system.

First of all, you need to check that there are no connected devices in the USB ports, such as flash drives or portable hard drives. They can cause a white screen in your iMac. You should also check that there are no bootable or system disks in the DVD drive. If the first two points are met, and the iMac still does not start, try to take out the RAM strips installed below, under the Apple logo, one by one.

There are usually two memory sticks. So try to take out one bar first and start up your iMac. If it still does not start and you see the "white screen" of the iMac, then try booting with the second RAM bar.
If the first three points are met, but you still see a "white screen" on the iMac, then most likely the hard drive is out of order. You can check the fact of a hard disk failure by temporarily replacing it with a similar one. For more information, see replacing the iMac hard drive.
For more detailed advice on malfunctions when the iMac "white screen" appears - call our service center.

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10 questions to “ iMac - White Screen”

1. Darya

   I turn on the iMac starts downloading halfway the download stops. When you reboot with the alt button held down, output to the hard disk, but it won't let you into the system. What could be the problem?

2. Darya

   I turn on the iMac starts downloading halfway the download stops. When rebooting with a button

3. Gevorg

   I turn on the iMac starts loading halfway down loading stops and brings an error sign

4. Sergey

   IMac - stopped loading (white screen and turns off) ... dancing with disk utility showed that the hard drive needs to be replaced