El Captain 11.1 , my imac goes to "sleep" with a black screen and can't be woken up. How do I resolve this?

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El Captain 11.1 , my imac goes to "sleep" with a black screen and can't be woken up. How do I resolve this?

Hi! I have an iMac Mid 2011. Updated to 10.11.1 last night (from 10.11). Now my computer is running slower. But more frustrating is that if I step away from my computer for more than 15 minutes, the screen goes black and nothing will "wake" it up. You can hear the computer running though the screen is black.

To wake it up, I've tried unplugging and replugging in my keyboard. As well as new batteries in my mouse, turning it off and on. And also pressing the space bar and other keys on the keyboard. The only solution is to manually power off my computer using the power button in the back. Unfortunately, this causes problems when the computer is powered back on via the button (including creative cloud app being completely blank). So then I have to restart the computer.

As a work around, I went to the energy saver preferences and changed the computer sleep and display sleep to NEVER. However, this does not "solve" the problem.

Any suggestions? Thank you!

iMac, OS X El Capitan (10.11.1), null

Posted on Oct 25, 2015 5:23 PM

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Answer 1

Linc Davis

Level 10

209,547 points

Oct 25, 2015 5:45 PM in response to rachaelobx

Resetting the System Management Controller (SMC) on your Mac - Apple Support

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Answer 2

rachaelobx Author

Level 1

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Oct 26, 2015 5:39 PM in response to Linc Davis

Linc, Thank you for the link. However, resetting the SMC did not solve the problem. Also a new problem is now occurring when I turned on the computer last night (after unplugging it), it start beeping very loud. It beeps in groups of three. I have had to boot up my computer three times since last night and each time the beeping has occurred. The first two times the computer finally started up. This last time its not starting up....just continues to beep in sets of three. Was finally able to shut the computer down so as to not hear the beeping. I do not know why this is happening or how to solve!

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Answer 3

Linc Davis

Level 10

209,547 points

Oct 26, 2015 6:41 PM in response to rachaelobx

Make a "Genius" a ppointment at an Apple Store, or go to another authorized service provider. You may have to leave the machine there for several days.

Back up all data on the internal drive(s) before you hand over your computer to anyone. There are ways to back up a computer that isn't fully functional—ask if you need guidance.

If privacy is a concern, erase the data partition(s) with the option to write zeros* (do this only if you have at least two complete, independent backups, and you know how to restore to an empty drive from any of them.) Don’t erase the recovery partition, if present.

Keeping your confidential data secure during hardware repair

Apple also recommends that you deauthorize a device in the iTunes Store before having it serviced.

*An SSD doesn't need to be zeroed.

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Answer 4

Brian14

Level 1

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Oct 27, 2015 6:57 AM in response to rachaelobx

I too am having this display sleep issue after updating to 10.11.1 this morning. Kind of annoying.

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Answer 5

rachaelobx Author

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Oct 27, 2015 8:23 AM in response to Brian14

Totally annoying Brian! 🙂 Last night ended up trouble shooting and resetting RAM which so far has solved the issue where the computer would not boot up but instead beeped 3 times with 5 second intervals. So now that my computer boots up properly...time to solve more el captain problems! haha

For the display sleep issue and others, I did a SMC Reset and then late last night ,once computer would boot up properly (after resetting RAM), I did PRAM Reset. Including links below that I referred to. Please research before doing the reset, not sure of all the risks that could be associated with PRAM. What I did find were many people who said to do the SMC first because the PRAM is supposedly a more invasive rest than a SMC.

Apple Support Communities: iMac SMC and PRAM reset:iMac SMC and PRAM reset

How, When, & Why to set the PRAM & SMC on your mac:http://thenextweb.com/lifehacks/2010/12/04/how-when-why-to-reset-the-pram-smc-on -your-mac/

I have not tested to see if the PRAM reset helped with the sleep issue yet (since this was late last night). (The SMC did not help.) Testing to see if sleep issue is corrected due to PRAM reset is on today's agenda.

That said: reseting the PRAM did make my start up and shut down a lot faster and seems to make my overall computer, OS system and internet work a lot faster! So that's a plus! Good luck!

PS I haven't done it yet, but have been looking into safe mode boot up if problems keep arising:Try safe mode if your Mac doesn't finish starting up - Apple Support

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Answer 6

AVAI_Rex

Level 1

12 points

Jan 25, 2016 3:13 PM in response to rachaelobx

I'm having this issue as well - my work MBP/R consistently "wakes" to a black screen from sleep, after having disconnected from an external monitor while the laptop was in sleep mode. In some cases the screen is actually "gray," with no background but the mouse dimly visible, and frozen. I've tried all of the usual troubleshooting techniques, including those mentioned by rachaelobx, to no avail. FYI, this has happened through literally every iteration of El Capitan, through 10.11.3. Along the way, I've done a wipe and reinstall of the OS, as well as applying the updates using the Combo update rather than the delta.

My latest attempt at a remedy is to turn off Automatic Graphics Switching, as I'd lay odds this problem has to do with Apple's El Cap feature of using GPU acceleration to draw Finder windows. If anyone else having this issue has already tried disabling graphics switching or is having the issue on a machine that only has Intel graphics, please post back.

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Answer 7

AVAI_Rex

Level 1

12 points

Jan 27, 2016 3:53 PM in response to AVAI_Rex

Update, possible fix: As I suspected, the problem seems to have been fixed by going to System Preferences -> Energy Saver and unchecking "Automatic graphics switching." Your mileage may vary, good luck!

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