Q: HELP! Black screen after startup after Yosemite installation

Turn on Mirroring:

CTRL + F1

Control and F1

This trick worked for me one time. After while the black screen issue came back and I have not been able to fix it using this method. Not any other methods, like resetting PRAM and SMC, worked. I have to say, Apple suucks--crapy bugs and crapy customer support!

Got it, but it took me forever to get there.

I had exactly the same issue and installed Yosemite numerous times to be defeated by the blank screed.  The answer is:

1 install and keep going until you get to the bank screen

2 power off

3 restart in safe mode - Apple explains this in OS X: What is Safe Boot, Safe Mode? - Apple Support but its really easy, Press the power button and Immediately after you hear the startup sound, press and hold the Shift key. The Shift key should be pressed as soon as possible after startup, but not before the startup sound.

4. the installation of Yosemite then completes

5. once you are up and running onYosemite restart the computer (click Apple logo in the top left of screen then click restart)

6 the restart takes a while (in my case about 20 minutes) but when you restart you are not in safe mode, the computer works and all is well!

Craig

Not sure why, but I feel like my problem went away. Apple released a couple of updates recently and one was security related. Perhaps that one was the fix and the problem was related to disk encryption!?

I'm on mid-2011 Air btw.

I have MBP 2008 and could only boot SAFE MODE after Yosemite.  Been like that 2 months.   Today, black screen, mouse cursor only.  PRAM reset got me into a screen that showed an installation update proceeding.  I had set auto-update for future OS updates and it must have stalled on an update.

Working again now but not a fun morning.

Update has once again caused the black screen problem. Pretty unimpressed that Apple has ignored this problem for so long. My update happened overnight - now I just have a black screen. Previous recommendations to fix not working this time. Come on Apple stop ignoring this problem.

Thanks for this, worked brilliantly, have done a restart and all.

Great advice...

Jim

Im running a MBP 2009. have had Yosemite on it for a while. Yosemite gave me problems running dual screen so i cut down to one. I still noticed the odd screen black out occasionally but normal systems resumed shortly after so no problem there for a while.

Tonight a new update installed itself and left me with the blank screen and cursor. I have tried to boot in safe mode, single mode, using  ctrl-s and holing down the power key. None of this has been any good.

I don't know how you can activates the time machine with black screen mode or how to get to any menus

Does anybody have any conclusive answers that are moving?

Finally resolved this.

Issue:

5K Retina iMac, out of the box did some setup for my client, saw there was an update pending, computer went to sleep.  When I woke it screen was black, mouse cursor moves around on the black screen.

- reboot, problem still there

- reset PRAM, problem still there

- single user mode, run disk check, OK, deleten login window plist and boot caches, problem still there

- boot from another mac, voila, mac logs in, so I know the display and hardware is working and this is an OS issue.

-enable VNC and VNC into mac, same black screen and cursor through VNC!

Resolution:

Found another post somewhere of a user who had this on Mavericks and they were able to resolve by hitting tab and typing in the username and password in the right combination on the black screen.  Essentially, typing in the username and password blind.  So I started typing in the username - tab - password and after the second try BAM - the login window appears.  I log in, it then finishes installing the update, and here I am at the desktop again.

HORRIBLE BUG HORRIBLE HORRIBLE HORRIBLE!

I have a very similar issue. After the display sleeps, when I wake it up, I only see the mouse cursor. Typing the password blindly works indeed.

I also tried to SSH into the problematic machine, then

    ps aux | grep loginwin

    kill -9 <loginwin process id>

then I get a working login window.

Sometimes only the 2nd kill helps.

The machine (27" 2K iMac late-2013) came with Yosemite, but we restored an Time machine backup onto it and later this problem appeared.

It had a freezing issue too, whenever we entered then exited from the time machine, so I've just reinstalled freshly (erasing the original partition) but the problem persisted.

I have NOT tried PRAM and SMC reset, but did a `sudo mv /Library/Preferences/com.apple.loginwindow.plist ~` and it didn't help either.

I upgraded to 10.10.3 and reset PRAM as the above! All fixed - Thank you!

I'm certain that the suggestion here are valuable. However, having to fix the issue by diving into command line for something as rudimentary as returning to the log-in screen, is ridiculous. I can manage the fix.  But this is not some esoteric function. It's part of the general user experience.

Problem with v-Sync cable. You must open imac and disconnect it. After, black screen problem is will be gone!

Thank you!

Thats all just

Thank you!