My computer is not working after I did the update how do I fix it?
How do I fix my computer after doing an update and it shows a black screen
MacBook Air 13″, macOS 10.14
Question marked as
Which update?
The general cure if it isn't failed HW, is to e-install the OS...
1. Start up from macOS Recovery
To start up from macOS Recovery, turn on your Mac and immediately press and hold one of the following combinations on your keyboard. Command-R is generally recommended, especially if you never installed macOS Sierra 10.12.4 or later.
Command (⌘)-R Install the latest macOS that was installed on your Mac.
Option-⌘-R Upgrade to the latest macOS compatible with your Mac.
Shift-Option-⌘-R Install the macOS that came with your Mac, or the closest version still available.
Release the keys when you see the Apple logo, a spinning globe, or a prompt for a firmware password. When you see the Utilities window, you've started up from macOS Recovery.