Sometimes, Mac won’t boot and prompts blank screen or an audible beep thus restricts you from accessing data stored on it. In such cases, you can troubleshoot problems that result in unbootable Mac. To do that, you have to access boot options where you can use Apple Hardware Test and other Mac repair options.
Here I have listed out various boot options available in Mac OS X, through which you can turn your unbootable Mac to bootable state.
- Booting from CD or Bootable Disc
If you want to boot using CD or any other bootable disc, then insert the disk and hold down the C key on your keyboard. It will help you to boot into Mac OS X.
- Apple’s Hardware Test
You can access Apple’s Hardware Test while booting from a disc which comes with your computer. Hence, hold down the D key while rebooting which help you to enter Apple Hardware Test.
- Reset PRAM and NVRAM
When PRAM and NVRAM gets corrupted, you fail to boot into Mac OS X. Hence, it is better to reset both PRAM and NVRAM. To do so, hold down the Command + Option + P + R keys until Mac restarts and you hear the startup sound for second time. After that, release the keys. It will reset PRAM and NVRAM.
- Selecting Bootable Devices
To enter boot screen, hold down Option key. Once you enter boot screen, check for bootable devices and select the one which you want to boot into Mac OS X.
- Eject, F12, or Mouse/Trackpad
If you unable to remove discs that are trapped in your optical drive, then restart your Mac by holding Eject key, F12 key, or your mouse or trackpad button.
- Network Boot
Hold down the N key while starting Mac to boot from network, in case your setup has compatible network server. If you use Option + N keys, then you can start from a NetBoot server using the default boot image provided.
- Target Disk Mode
If you want to recover files from unbootable Mac, then Target Disk Mode boot option is best choice. So, press T while starting Mac to enter Target Disk Mode.
- Safe Mode
To enter Safe Mode, hold down the Shift key while rebooting your Mac OS X. This boot option loads only required kernel extensions and disables non-system fonts, all startup items, and login items that are not required.
- Verbose Mode
Using Command + V keys, you can boot your Mac into Verbose Mode. This key combination will show a terminal-like interface during startup. It consists data that is important for booting. And also allows to spot startup problems.
- Single User Mode
To boot your Mac into Single User Mode, use Command + S keys. In this mode, you can communicate with your computer through text input. This mode helps you to fix startup issues or alter software which prevents startup.
- Lion Recovery Mode
In case, you have Mac OS X Lion on your computer, then hold down Command + R keys which helps you to load into Lion Recovery Mode.
If you fail to boot into Mac even after using these boot options, then try Remo Mac Recovery and get back your data from unbootable Mac. The tool can also be used to restore a deleted partition on Mac and to recover data from formatted Mac partition.