If the Mac has problems starting correctly and a recovery becomes necessary, there is no need to go to the Apple Store because the MacOS system has all the tools to correct the errors inside it, restore the key files and solve the startup problems.
To use these tools, however, you need to study the user manual and know which keys to press to execute them.
In this article we make a summary of all the ways to restart the Mac in recovery mode, test and fix the startup of the Mac, iMac or MacBook, thus discovering the shortcuts and key combinations that must be pressed immediately after turning on computer, before the boot sequence starts, before you see the gray screen and the Apple logo.
1) To start the Mac in recovery mode, press the Command - R keys together
Pressing Command and R starts the Mac in recovery mode which includes a series of utilities to be used to make the Mac work again.
Then there are the Disk Utility to check and repair the system drive, Time Machine backup recovery and reinstallation of the MacOS system.
All information and instructions on how to use MacOS Recovery are on the Apple website.
2) Boot the Mac from an external drive with the Option key .
Pressing the Option key at startup displays a list of the Mac bootable drives.
You will then see the system disk, the recovery partition, any BootCamp partition if any and the DVD player (if any).
If a Linux USB stick is inserted on the Mac, it can be run and started.
3) Apple Diagnostics / Apple Hardware Test with the D key
If you hold down the D key at Macbook or iMac startup, the Apple Hardware Test or Apple Diagnostics is displayed depending on the Mac model.
This test is used to make a quick or thorough check of the Mac hardware to see if some internal part is broken or if everything is intact.
This is the first test to be performed in case of problems on the Mac, because it allows us to exclude that something is broken inside that can only be repaired in an Apple Store.
If there is nothing broken, you can always reinstall MacOS to go back to using your computer as new.
The guide on Apple Diagnostic is on the Apple website.
4) Reset the NVRAM (or PRAM) with the Option + Command + P + R keys
Hold the Option + Command + P + R keys while the Mac restarts and keep them pressed until the Mac restarts a second time to test the NVRAM (or PRAM on older Macs), abbreviation for non-volatile RAM, where the Mac saves specific preferences when it is turned off.
NVRAM manages the volume, resolution, time zone settings and boot disk.
For more details, see the guide on how to reset NVRAM on the Apple website.
5) Restore SMC : Shift-Ctrl-Option
If resetting the NVRAM is not resolved, the next step is to reset SMC, which is the system management controller.
This is reset on the MacBook by holding down the Shift + Control + Option keys while on the Mac Desktop just unplug the power cable for 15 seconds, reattach it and then restart the computer after 5 seconds.
Resetting SMC can help solve many hardware configuration problems, such as if the fans keep spinning even when the Mac is idle or if it never goes to sleep or if the keyboard backlight doesn't work.
To learn more, the guide to SMC on the Apple website
6) Verbose Mode with the Command + V keys
When something doesn't work during Mac startup, try holding down the Command + V keys to switch to Verbose mode.
In this way, if you have technical experience, you can read the list of hidden operations and processes that are performed during the startup procedure and understand what is wrong.
If FileVault encryption has been enabled, you must hold down the keys until the login screen appears.
If you have a firmware password, you need to disable it.
7) Safe Mode : Shift
If there is any program that locks your Mac during startup, you can start your Mac in safe mode (similar to Windows Safe Mode) by holding down the Shift key during startup.
You can also restart your Mac in Safe Mode using the Terminal and running the command:
sudo nvram boot-args = "- x"
To exit safe mode, the command must be executed in Terminal
sudo nvram
When using this mode, the Mac disables almost everything except the basic system services.
For more details, you can read the Mac guide on the Apple website.
8) Single user mode : Command + S
The single user mode allows those who are experts in UNIX commands to start the Mac in command line root mode.
The command screen allows you to execute Terminal commands and solve system problems as an expert.
9) Target disk mode : T button
To copy data from one Mac to another Mac, you can start the computer in target disk mode.
The two Macs must be connected using a Thunderbolt, Firewire or USB-C cable.
This mode has a somewhat limited application, and is documented on the Apple website.
READ ALSO: How to repair the Mac, solve MacOS problems and errors
To use these tools, however, you need to study the user manual and know which keys to press to execute them.
In this article we make a summary of all the ways to restart the Mac in recovery mode, test and fix the startup of the Mac, iMac or MacBook, thus discovering the shortcuts and key combinations that must be pressed immediately after turning on computer, before the boot sequence starts, before you see the gray screen and the Apple logo.
1) To start the Mac in recovery mode, press the Command - R keys together
Pressing Command and R starts the Mac in recovery mode which includes a series of utilities to be used to make the Mac work again.
Then there are the Disk Utility to check and repair the system drive, Time Machine backup recovery and reinstallation of the MacOS system.
All information and instructions on how to use MacOS Recovery are on the Apple website.
2) Boot the Mac from an external drive with the Option key .
Pressing the Option key at startup displays a list of the Mac bootable drives.
You will then see the system disk, the recovery partition, any BootCamp partition if any and the DVD player (if any).
If a Linux USB stick is inserted on the Mac, it can be run and started.
3) Apple Diagnostics / Apple Hardware Test with the D key
If you hold down the D key at Macbook or iMac startup, the Apple Hardware Test or Apple Diagnostics is displayed depending on the Mac model.
This test is used to make a quick or thorough check of the Mac hardware to see if some internal part is broken or if everything is intact.
This is the first test to be performed in case of problems on the Mac, because it allows us to exclude that something is broken inside that can only be repaired in an Apple Store.
If there is nothing broken, you can always reinstall MacOS to go back to using your computer as new.
The guide on Apple Diagnostic is on the Apple website.
4) Reset the NVRAM (or PRAM) with the Option + Command + P + R keys
Hold the Option + Command + P + R keys while the Mac restarts and keep them pressed until the Mac restarts a second time to test the NVRAM (or PRAM on older Macs), abbreviation for non-volatile RAM, where the Mac saves specific preferences when it is turned off.
NVRAM manages the volume, resolution, time zone settings and boot disk.
For more details, see the guide on how to reset NVRAM on the Apple website.
5) Restore SMC : Shift-Ctrl-Option
If resetting the NVRAM is not resolved, the next step is to reset SMC, which is the system management controller.
This is reset on the MacBook by holding down the Shift + Control + Option keys while on the Mac Desktop just unplug the power cable for 15 seconds, reattach it and then restart the computer after 5 seconds.
Resetting SMC can help solve many hardware configuration problems, such as if the fans keep spinning even when the Mac is idle or if it never goes to sleep or if the keyboard backlight doesn't work.
To learn more, the guide to SMC on the Apple website
6) Verbose Mode with the Command + V keys
When something doesn't work during Mac startup, try holding down the Command + V keys to switch to Verbose mode.
In this way, if you have technical experience, you can read the list of hidden operations and processes that are performed during the startup procedure and understand what is wrong.
If FileVault encryption has been enabled, you must hold down the keys until the login screen appears.
If you have a firmware password, you need to disable it.
7) Safe Mode : Shift
If there is any program that locks your Mac during startup, you can start your Mac in safe mode (similar to Windows Safe Mode) by holding down the Shift key during startup.
You can also restart your Mac in Safe Mode using the Terminal and running the command:
sudo nvram boot-args = "- x"
To exit safe mode, the command must be executed in Terminal
sudo nvram
When using this mode, the Mac disables almost everything except the basic system services.
For more details, you can read the Mac guide on the Apple website.
8) Single user mode : Command + S
The single user mode allows those who are experts in UNIX commands to start the Mac in command line root mode.
The command screen allows you to execute Terminal commands and solve system problems as an expert.
9) Target disk mode : T button
To copy data from one Mac to another Mac, you can start the computer in target disk mode.
The two Macs must be connected using a Thunderbolt, Firewire or USB-C cable.
This mode has a somewhat limited application, and is documented on the Apple website.
READ ALSO: How to repair the Mac, solve MacOS problems and errors
