Mac users must know the different boot modes and keyboard combinations to troubleshoot startup and other issues. But it is important to note that most of the boot options and keyboard combinations mentioned are for Intel-based Macs. The options for M1 and M2-based Mac computers have changed. The options can be accessed by turning off your Mac > powering on your device, and holding the power button until you see the startup options screen. As the macOS recovery mode is launched, users can access the other boot modes, including Startup Manager, Safe Mode, Target Disk Mode, and Set a Default Startup Disk. Verbose mode and other advanced options are hidden away, and resetting SMC and NVRAM/PRAM is no longer required.
Take a look at the macOS boot modes and learn the key combinations to troubleshoot the problem you have encountered with your device quickly.
Safe Mode or Safe Boot is a good step to try if your system needs troubleshooting for startup problems. This mode forces the device to load on the bare essentials it requires to start the OS.
Then, the startup disk checks for errors and makes the necessary repairs. It only uses essential kernel extensions.
The Safe Mode prevents the login and startup items from launching when the device starts. In addition, it disables all the custom user-installed fonts and clears system caches.
Start your Mac in Safe Mode by restarting or turning on your Mac > pressing and holding the Shift key until the login window appears > log into your device. You may be asked to log in again, and on the first or second window, you’ll see Safe Boot in the menu bar.
Verbose mode replaces Mac’s default startup graphics with an in-depth status report of what’s happening when your system starts up. However, it does not restrict anything from loading and does not boot into a command line environment.
Verbose mode is ideal when your system hangs on boot. It ensures you can see what is interrupting the boot process so you can quickly take steps to remedy the problem.
To start Verbose mode on your system, shut down your device. Then, press the power button to switch it on again. Finally, press and hold the Command + V keys when your device starts.
Startup Manager/Boot from USB
Apple’s Startup manager prevents your system from booting the default startup volume. Instead, users get a list of the connected volumes, including external drives and USBs. This is critical if users need to boot their system from USB or wish to install Windows from a USB stick.
You can use the Option key to access the Startup manager or boot from USB. If you use a non-US Mac keyboard, the Option key will be replaced with the Alt key.
Recovery mode helps Mac users solve several problems. The recovery partition is separate, and users can use it to repair disks using Disk Utility, restore their Mac by reinstalling macOS, or access the Terminal.
To start the Recovery mode, press and hold Command + R or Command + Option + R.
Apple Hardware Test/Apple Diagnostics
Apple Hardware Test or Apple Diagnostics are troubleshooting tools that help users identify hardware problems. So, users can attempt to fix the device or decide to replace their machine.
However, these tests don’t offer much information about the hardware problem, and if you want more information, you can use Apple Service Diagnostic instead.
Suppose you want to start the test from the Internet, press Option + D on the keyboard. On your computer, you can press D to let your system run Apple Hardware Test or Apple Diagnostics.
The SMC or the system management controller is a chip on Intel-based Macs. The SMC controls several aspects like power management, fan speeds, etc. If your system has problems, you can reset SMC by pressing Shift + Control + Option.
Although most Mac computers use this combination to reset SMC, some models may require you to unplug the power cord or remove batteries.
Non-volatile RAM or parameter RAM holds information about the system’s current configuration. It includes the volume, date and time, desktop settings, etc. If you run into problems related to mouse scrolling, sound, or keyboard, you can reset PRAM/NVRAM by pressing Command + Option + P + R.
Use the key combination when you immediately power up your device after shutting it down. When your system starts up, let go of the keys.
Boot From Optical (CD/DVD) Media: C
If your Mac is old enough to have an optical drive, you can create DVD or CD images for installing macOS or other OS like Windows and Linux. While your computer boots, hold the C key to ignore the startup volume in favor of the bootable optical media.
The Bottom Line
These are some Mac boot modes you must know so you can quickly troubleshoot your computer without calling the technician.