a. If you recently installed memory or a new drive (HDD or SSD), make sure that it’s compatible and installed correctly. If possible, rem

How to troubleshoot your Mac not booting to MacOS

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2021-04-18 04:29:43

a. If you recently installed memory or a new drive (HDD or SSD), make sure that it’s compatible and installed correctly. If possible, remove it and test with original memory or drive.

i. Prohibitory symbol (Circle with a line or slash through the center) means that the selected start up disk contains a Mac OS, but not the correct version for your Mac. You need to reinstall macOS on that disk.

ii. Question mark (Folder with a question mark) means that the selected start up disk isn’t available or doesn’t contain a macOS. Reinstall macOS.

iii. Blank or empty screen may appear once or more during startup. It can be black, gray, or a desktop picture. If an image doesn't appear after a few moments, make sure that your display is turned on, connected, and has its brightness turned up.

iv. An Apple logo with a progress bar means your Mac found its startup disk, which is a built-in disk. As startup continues, you should see a progress bar or indicator, with or without the Apple logo. If you’re updating or reinstalling macOS, this stage can take much longer to complete. If your Mac cannot find a local startup disk, it will attempt to use a network startup disk.