PhilipAnthony

Q: iMac screen goes black, but system runs fine in background

Just started happening, and repeating more an more. Screen goes black (as if in power save mode), however system continues to run in background. To test this, I carried on typing and email, when I used the power button to put to sleep, then again to wake, all typing is there. This proves it is only the display going off. Any idea what is going on here - I've viewed old discussions, and others have similar issues but no solutions out there!

iMac, OS X Mavericks (10.9)

Posted on Nov 18, 2013 5:52 AM

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Q: iMac screen goes black, but system runs fine in background

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  • by ivanfromguatemala,

    ivanfromguatemala ivanfromguatemala May 10, 2016 9:36 AM in response to PhilipAnthony
    Level 1 (4 points)
    May 10, 2016 9:36 AM in response to PhilipAnthony

    I had this problem and I read this thread, honestly I was worried about this but luckily I found a very simple solution.  I opened my Late 2009 Imac 27" following instructions for that and I used compressed air to clean out the dust inside and everything came to normal.  Was it slowing the ventilators? I don't know I tried before with more ventilation but that didn't work, maybe there was dust over a sensor or something else.  Since I applied compressed air generously all over there inside without opening anything more than the lcd panel for that the problem dissapeared.

  • by Strek,

    Strek Strek May 27, 2016 8:36 AM in response to kazbluesky
    Level 1 (4 points)
    May 27, 2016 8:36 AM in response to kazbluesky

    I'm having the same issue with iMAC 27" mid 2010. If I try to use max brightness then no issues at all.

    But I'm wandering does the max brightness screen is causing temperature failure on some sensor LCD, GPU or?

    If not, I guess that's the solution for me.

  • by ScottSAZ,

    ScottSAZ ScottSAZ Jul 9, 2016 8:20 AM in response to PhilipAnthony
    Level 1 (4 points)
    Jul 9, 2016 8:20 AM in response to PhilipAnthony

    Heat Issue - I had this same issue with my 2007 imac after I upgraded to ElCap.  The screen would go completely black while using the computer and it would only come back on after waiting awhile or pressing the computer power button multiple times.  I tried everything suggested here, PRAM reboot, new keyboard, deleting preference log in profiles. Then I thought, what if the iMac is getting too hot and something is shutting down........I downloaded Mac Fan Control https://www.macupdate.com/app/mac/47386/macs-fan-control and set the available fans to turn on more frequently when upper temperature limits were reached.  I had no idea my CPU and GPU were running at over 170 degrees.  Well this SOLVED the entire issue of my screen going black.  I have been running the imac now for 4 days, NO Black screen issues at all and the computer runs perfectly.  Now, running the fans more frequently or at a higher RPM may limit there life a little, but a new fan is easy to replace.  Hope this helps, one more free thing to try.

  • by Juan W.,

    Juan W. Juan W. Sep 1, 2016 2:58 AM in response to PhilipAnthony
    Level 1 (4 points)
    Sep 1, 2016 2:58 AM in response to PhilipAnthony

    I tried a lot of stuff ;

     

    - New keybord

     

    - Screen settings

     

    - Hitting my imac and calling it rude words

     

     

    Seems the best thing that helps is Macs fan control , once installed I still had it a few times but when I man. encreased the fan speeds the temp. stays low and my screens doesn't go black anymore ...

     

     

    grtzzz Juan

  • by tygb ,

    tygb tygb Sep 1, 2016 4:34 AM in response to PhilipAnthony
    Level 2 (197 points)
    Mac OS X
    Sep 1, 2016 4:34 AM in response to PhilipAnthony

    I am not using OS X mavericks but just guess out for settings .

     

    Please open system preferences and click on built - in display .

     

    Check the options : Resolution default for display and adjust the brightness automatically .

  • by bowlerae,

    bowlerae bowlerae Sep 2, 2016 12:36 PM in response to PhilipAnthony
    Level 1 (4 points)
    Mac OS X
    Sep 2, 2016 12:36 PM in response to PhilipAnthony

    ---Please bare with me on this long post---

     

    Hello all, I'm in a similar boat. Seems like I'm having several issues crop up right at once and after a certain point, it's costing me more money to repair the computer than to get a new one.

     

    In early July this year my screen on my 2011 iMac started bugging out. Shutting down the computer and tried rebooting with no success. Took the computer in to a highly rated repair shop near me. They said the GPU died so I had them install another one. That cost $650.

     

    Upon receiving my computer again, one of my two SSD drives failed and because the two drives were raided together my whole computer was unbootable. This was the same day I got my computer back from the shop, so of course I'm convinced they did something. I was able to unraid and reformat one of the drives by booting from an install USB. One drive appeared to be severely corrupted. I was finally able to recover the corrupted SSD drive, or at least I thought, but then the drive was intermittently being detected. I figured maybe there was a lose connection. I soldiered on with only one working SSD but otherwise working computer.

     

    About two weeks after that, my computer fell asleep while I was gaming on my Xbox and listening to Spotify on my computer. I shake the mouse to wake up the computer and change the song but the screen remained black (song continued to play and I could even click in the right spot and pause the song). I was forced to  hard reset the computer. Trying to boot up the computer the screen remained black. I searched online for possible solutions. I did PRAM and SMC reset a dozen times, tried changing my brightness, etc but nothing ever worked. Finally hooked the computer up to an external display and was able to operate it no problem.

     

    I finally took my iMac back to the repair shop, I don't know if they did something or I'm just having all of these computer issues happening in the course of 4 weeks. I asked them to make sure they cables were all secure and nothing was loose.

     

    I finally heard back and they said it's either 1.) The inverter board which would cost $150 to replace, 2.) the LCD which would cost several hundreds to replace, or 3.) they just absolutely would not know what it was.

     

    Anyone have any thoughts of what it could possibly be?

     

    I honestly don't know what to do at this point because I bought this computer only a year ago on eBay. I bought it used but its has a lot of great upgrades like 4 TB SSD raid and 2 TB HDD backup, the read/write speed is 4x that of a normal out-of-box Mac plus fully upgraded RAM, etc. It costs $1100 originally which wasn't so bad because I sold back my older iMac for $700 so I only got the computer for about $400. But after the GPU replacement of $650 and now whatever issue this is, I could have just bought a new computer.

  • by Juan W.,

    Juan W. Juan W. Sep 2, 2016 5:45 PM in response to bowlerae
    Level 1 (4 points)
    Sep 2, 2016 5:45 PM in response to bowlerae

    Hi ,

     

     

    I know the problem and it is a heath issue instead of a hardware issue.

     

    Your screen goes black because your computer needs more cooling  HD , CPU

     

    You have to install Mac fan control so you can manualy encrease the speed of the 3 fans in your computer so the core temp drops. When you run spotify and some games it gets hot.

     

    Cheers

  • by Anonmusic,

    Anonmusic Anonmusic Sep 8, 2016 11:48 PM in response to PhilipAnthony
    Level 1 (4 points)
    Sep 8, 2016 11:48 PM in response to PhilipAnthony

    I came across this issue on my late 2009 iMac 27 inch recently (Its been working fine up to Jan 2016 this year:

     

    Symptoms:

     

    -Screen panel goes black randomly while working.

    -Screen goes off if the brightness is above 3/4 bars (for me it was progressive  - 4 bars was ok, then it only stayed lit at 3 bars.

    -Screen never goes off if the brightness is 100%

     

    It certainly 'feels' like a hardware fault...

     

    Ideas proposed so far:

     

    Heat Related Hardware failure: Replacement of either Logic Board, Display Backlight (very expensive) Display Inverter ( not that expensive)

    Risks: Permanent damage to your computer - further problems from taking everything apart.

     

    My solution:

     

    I was ready to sell my beloved iMac due to what I thought was an expensive hardware issue / wear & tear. Its NOT! Don't sell your iMac just yet!

     

    Turns out there was a simple fix for me:

     

    Install F.lux on your iMac. For some reason after I installed F.lux, I have no further problems with the display blanking.

    I've been using what I thought was a dead iMac now for the last 72 hours with no problems at any brightness level.

     

    To make extra sure, I disabled f.lux on my machine (Menu -> Disable) and it still works. I'm not sure whats really going on, but I believe F.lux is overriding the default behavior of the panel and preventing the blanking from happening.

     

    Please try it out and report if you experience the same thing

     

    After a serious scare, have a whole new iMac again!

     

    Thanks,

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