Kit Guide: Fixing a blank screen after OS X Mavericks 10.9.3 update


This guide helps you if you've downloaded the 10.9.3 update to your Mac, and now have a blank screen when you turn it on.

Fixing the problem


To fix the problem, you can try logging in while the screen is blank. This can be tricky though as you can't see what's onscreen.

Luckily, you can fix it by booting the Mac into 'Single User Mode', which is an advanced mode used to fix problems. We've written some steps below to help.

Fix 1: Logging in while the screen is blank


Turn off the Mac by holding the power button for 5 seconds.


Hold down the Shift key, and while holding it, press the power button.


When the blank screen shows, press the first letter of your username. For example, if your username is Daniel, press the letter D.


Press Enter, then type your password, and press Enter again.

You should now see the spinning beach ball for a few seconds, and the screen should show as usual.

Fix 2: Using Single User Mode


Turn off the Mac by holding the power button for 5 seconds.


Press the power button to turn the Mac on, and immediately hold the command and S keys. The Mac will load in Single User Mode.


Type ' mount -uw / ' and press Enter.


Type ' cd /Library/Preferences ' and press Enter.


Type ' mv oldlogin ' and Press Enter.


Type ' reboot '  and press Enter.


When you get to a black screen, press Enter, and you'll be able to log in as usual.

Hopefully, that's all the help you need. If the problem still isn’t fixed though, click here to here to get in touch with an expert from Team Knowhow.

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