How to fix a Mac that hangs on a gray screen on startup

Problems booting Macs come in many different forms, but hanging on a gray screen can be one of the most troublesome issues because many of the causes can cause this error. In addition, there are many other problems on the Mac that are mistaken for Mac errors hanging on the gray screen.

What is a gray screen problem on a Mac?

The truth is that this error does not always appear on a gray screen. A crashed Mac problem when booting can also appear as a black screen. In fact, the screen is so dark that you might mistake it for power off. This is especially true for Macs with an integrated Retina display, such as a Retina iMac model without a power indicator light.

This boot problem is called a gray screen problem, because the screen will turn gray during the boot phase when the problem occurs. Instead, recent Mac Retina models have black or very dark screens instead.

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Gray screen problems occur after the Mac is turned on or restarted. The feature of this problem is that the screen changes from blue when power is grayed out, although you may not see the blue screen because it usually disappears very quickly.

It is also possible that the specific Mac model you are using does not display the blue screen. Apple streamlined the boot process and displayed fewer screen types during the boot process.

You can only see the gray screen, which may also include the Apple logo, spin or prohibition sign (a circle with a slash above). In any case, the Mac seems to be frozen. There is no unusual noise, such as a rotating optical or fan drive that produces excessive noise; It is just that the Mac does not continue to log in or to the desktop.

Another boot error that is mistaken for this problem is that the screen turns gray with a folder icon and a question mark blinks. It is a separate problem, very easy to overcome (will be mentioned in another article).

How to fix the problem that the Mac hangs on the gray screen on startup

Method 1: Disconnect all peripheral devices

Temporarily remove all peripheral devices for the duration of the procedure according to the steps below (unless otherwise noted).

1. Turn off the Mac by pressing and holding the power button.

2. If possible, remove the Ethernet cable, audio input / output cable, headphones and any other peripheral devices.

3. Turn on the Mac again.

Important note : Do not disconnect the keyboard, mouse or screen. If the keyboard or mouse is connected via a USB hub, skip that hub by plugging the keyboard and mouse directly into the Mac to check.

One of the most common causes of gray screen problems is the problem with the device's peripheral or cable. When a problematic peripheral is plugged into the Mac, it can prevent the autostart from happening and cause it to stall while waiting for the peripheral to respond to the command.

The most common form of this problem is a peripheral device or its cable malfunctioning that causes one of the batteries to signal on one of Mac's ports to be 'stuck' at high / low voltage conditions. , short-circuit earth or positive voltage. Any of these conditions can cause the Mac to freeze during the boot process.

If the Mac restarts without a problem, you will know that it is a problem with the peripheral. You need to turn off your Mac, reconnect a peripheral device and then restart the Mac. Continue the process of reconnecting to other peripherals and then restart the Mac until you find a problematic peripheral.

Note : Remember that the problem may also be due to the peripheral device's cable, so if you plug in the peripheral again and it causes a gray screen problem, try the peripheral with a new cable. before you completely replace that device.

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Try changing the currently used mouse and keyboard to alternative devices that you know work well, then reboot your Mac. If you do not have a backup device, simply disconnect the currently used mouse and keyboard, then reboot by pressing and holding the power key.

If the Mac can access the login screen or desktop, you will need to determine if the problem is with the mouse or keyboard. Try plugging each device one by one and then rebooting to confirm.

Method 2: Start the Mac with Safe Boot

If no external device or cable fails, try booting the Mac using Safe Boot mode. To do that, first disconnect all peripheral devices, except for the mouse and keyboard.

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During the Safe Boot process, the Mac will perform a boot drive check. If this directory is intact, the operating system will continue the boot process by only loading the minimum number of kernel extensions required to boot.

If the Mac successfully booted into Safe Boot mode, try restarting the Mac in normal mode. If the Mac boots up and enters the login screen or desktop, verify that the boot drive is working correctly. Chances are this drive has some problems that need fixing. You can use the Disk Utility tool to check and repair the boot drive, even in the worst situations, it may be necessary to replace the drive.

Method 3: Reset PRAM and SMC

If you cannot start the Mac in Safe Boot mode or the Mac starts in Safe Boot mode but does not start normally, try resetting PRAM and SMC.

Note : PRAM and SMC resetting returns Mac hardware to the default settings. For example, the audio levels are set to default, the internal speakers are set as the audio source, the display options and brightness are also reset.

Reboot the Mac after resetting PRAM and SMC. If it works normally, reattach each peripheral, restart the Mac after each time, to verify that none of them cause the original gray screen problem.

Method 4: Remove all but the minimum amount of RAM from your Mac

If you have added any RAM to your Mac after purchasing it, remove that RAM and see if the Mac boots normally.

If this is the case, then one or more RAM modules have failed and you will need to replace it. However, you will be able to continue working with the Mac until there is a replacement RAM.

Important note : Unfortunately, some troubleshooting steps may cause you to lose some, even all data on the boot drive. So before taking these steps, be sure to try this method to fix this RAM first.

Method 5: Repair the boot drive by booting into external media

Please boot into external media, such as installation disk, to verify that the boot drive has a problem.

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Boot from OS X or macOS installation disc:

1. Insert the installation DVD into the Mac's optical drive.

2. Turn off the Mac.

3. Boot the Mac while holding the C key. This tells the Mac to boot from the media in the optical drive.

Boot from Recovery HD:

1. Turn off the Mac.

2. Start the Mac by pressing Command + R

Booting from another boot drive, such as an external hard drive or flash drive containing an operating system capable of booting:

1. Turn off the Mac.

2. Connect the external hard drive or plug the flash drive into the USB port.

3. Start the Mac by holding down the Option key.

4. List of available drives with OS X or macOS installed with boot capability will appear.

5. Use the arrow keys on the keyboard to select the destination drive, then press Return or Enter .

If the Mac boots with any of these methods, repair the boot drive with the instructions in the Disk Utility section.

If you boot from installation DVD or HD Recovery, use the same basic steps, but the Disk Utility application will not be in the Applications folder . Instead, you'll find it as an item in Apple's menu bar (if booting from the installation DVD) or in the window of Mac OS X Utility (if booting from Recovery HD).

Note : If at this time the repair process does not work, the boot drive may need to be replaced, including reinstalling the entire operating system.

Tip : If you can't repair the boot drive using Disk Utility, try a third-party utility. Even if you can repair the boot drive, it needs to be replaced in the near future.

Method 6: Boot into single-user mode to repair the boot drive

One of the lesser known special startup modes is called single-user. This special boot mode boots the Mac onto the screen that displays information about the boot process.

The screen looks like an old terminal, but is similar to the boot sequence in many Unix and Linux operating systems. In fact, many similar commands are available from the prompt.

When in single-user mode, Mac does not automatically load the GUI, including the desktop. Instead, it stops the booting process after launching the basic operating system kernel.

Method 7: Remove, replace the boot drive or bring the Mac to a service center.

If you cannot boot the Mac using any of the methods listed above, your boot drive may have been corrupted or there is another internal component preventing the Mac from booting.