Lucarino what you need to do, when the screen turns black, press option, command and eject at the same time. this should put the mac to sleep, then press the keys again and it should wake the mac up, and the screen should be back, then lower your brightness so it doesn't happen as often
I've had this problem as well. I just got it to stop though. Here's what seems to have worked for me: It was either A. Switching to a wired keyboard or B. Blowing compressed air through the vent covers to better increase air flow to computer. To do the second one, you can just peel off the black glass screen (it's apparently only attached by magnets. Peel from top) and shoot the compressed air down through the ventilation holes. I don't know which fixed it, but now I'm at full brightness with no shutdown, when I previously could only run with ZERO brightness. Hope this helps someone else.
Tysm I wasn’t even reading this properly all I did was turn my brightness all the way down then a bit up again and it works fine now no shut down for the past 2-3 hours thanks dude 🙏🏾
It's got me too, First iMac I ever paid full price, for and it was perfect for 2 years, well almost perfect. I did see a video flicker ever now and then. Bought it in 6/2010. It's a 21.5 3.06ghz 4megs 1TB. First the DVD stopped working, then the hard rive died, worked off external, then screen went black, turned it off in disgust since I was a Mac Consultant and shoved it in a corner. You could get the screen to come back by pressing the power button in quickly and release while moving the mouse for awhile. Now it's just black with the fan running wide open. Can't even access it with remote access software. I used to love Apple the company, now I still like the products but a company should make right things they screw up. It's pretty cleat that since SO MANY people are having this issue it's a design flaw. But I've seen Apple do it before, just say, Oh Thats End User error.
Hi. Guys If it passes a 3D stress test like Heaven or Furmark and similar on Boot Camp and the stress test for the CPU. It's not the GPU. One just needs to adjust the fans, HD at 2200 rpm, the CPU at 2800. If it doesn't pass the 3D and CPU stress tests, that's the time to "reball" the GPU chip with torch or have it repaired. But try to adjust the fans first using smcFanControl for OS X and the Macs Fan Control for Windows. God bless. Rev. 21:4
Having exact same problem with 2011 27" iMac. Took to the Apple Store and they found no problems with it. But next day at problem is back. Can not get to the login screen without it going black. 😡😡😋
I've had this same problem. I Think it is a heat related engineering issue related to the display software. When lowering the display brightness it occurs less frequently. I also installed SMC fan control and put the settings on that up to 3000 on all 3 fans. That runs a bit noisy but the issue occurs less often as the computer is kept cooler. I also think it helps to blow the dust out of the machine as all those tiny holes keep hot air in if they get clogged over time. To do this I simply slipped guitar picks to the edge under the screen then pull it away. It is held on by magnets and will come away easily when you edge the guitar picks around it. Then I undid the screws that release the video screen and just lifted it up enough to be able to blast it out with a hair dryer. That way you don't have to mess with any cable connectors. It's best to do this after the machine is cool and only for a few seconds each time as the hair dryer gets real hot and could effect components otherwise. Just give it a good blasting to clear those holes so it can breathe. Then, this part will sound odd, but by turning my screen up to full brightness I no longer have the problem. Yet when I come away from full and come down a few notches it still occurs intermittently. I can use command, option, eject to quickly get it going again and then I am able to lower the brightness to below halfway which once again reduces the heat energy and allows the screen to stay operations. The weird part is that it does work when on full brightness. Anyway, I hoe this helps somewhat.
Tomorow 9-12-15; I will take the LCD out of the iMac 24 inch, and put it in another iMac 24 inch that i have. If this continues, my guess is that the backlight is going bad on the mac..... #2 My second guess that the there is the Detachable video card (if one) needs to be reballed with heat and liquid (clean flux) with a good heat gun. REPASTE with thermal paste (artic sylver ) and maybe that will work.
14 years later my 20 inch version likes to flicker on very low brightnesses. But even half way seams to work fine. I think mine is due to its age of 14 years
I have the same problem,i press cmd alt and eject keys altogether,this re-sets the graphics adaptor and usually it brings the screen out of the stupid black screen
+Steve Biggins : Peace, Does this work for you what you stated? And do you agree with the rest, that it is Either a Logic board isue? Video board ? Or the BACK LIGHT? ;;;;Command(apple) = Control (windows ) ; ALT (WIN) = ALT(apple) ; F12(win) = EJECT button.... -Out
I'm having this exact problem on a refurbished iMac I had less than a week before it started doing this. Pressing the power button twice slowly brings it back, sometimes for half an hour, sometimes for one second. It just did it again repeatedly more than 30 times before I gave up and turned it off. Can no one give any straight answer about this problem? It seems wrong that this is such a common problem that Apple must be aware of and they are refusing to assist people. If it's a design flaw they should have a duty to assist.
Just bought the 27" for $50 and has the same exact issue. The seller had it diagnosed by mac technician and came back with as a bad video card. The seller understandably doesn't want to pay $500.+ for a new card…I just finished removing the card (after 3 hours) and will try the baking method.
Happens to me all the time in bootcamp. Took it and apple checked it saying the comp is perfect, that it's a windows problem and that there is nothing they can do u.u
I had exactly the same problem on a similar Imac. I changed the standby settings so that it never goes to sleep mode and the problem seems to be solved now. I guess with some particular settings, there is a conflict between different standby modes. Well, hope I was clear enough.
I had the same problem, I installed a utility that shows the temperature and not overheating? now my screen is black and no longer Revien. I accede to my mac with teamviewer or a screen on tunderbold
Ivan, Did you have exactly the same issue? as on the video... because i have the same problem, but i can watch video, run heavy application and within an hour (or less) of work it turns black as on the video. This thing started happening when i installed java update 1 week ago.
Could it be the graphics card? You have enough time to load up iTunes or something and test to see if the processor is still running when the screen goes off, if the sound stops as well you have a processor problem. Reboot and load up Activity Monitor and observe the processor core activity graph, if you see one core flat line first, then later the screen shuts off, it would likely be a over heating issue, maybe the fan has packed up.
Did I miss something?
Mine does rhis too. Black screen, audio stutters (when overheated) and restars multiple time until I hold the power button
Thank you for showing me how to fix it. No black screen anymore, thank you so muuuuuch!
GPU 100%
I hate that UA-cam took away dislike count
SCPkfudlfkfjfu djfodifi65
i have that problem. it doesnt happen in safe mode however. it will run indefinitely and the screen wont go dark, have you foud a real solution yet?
Dreadful
I have a similar problem. The iMac gives a little noise when the button is pressed and it turns on, then black. No startup noise just black.
sameeeeee plz helpme
I had this problem today and I just used the vacuum cleaner and now it works,.
I'm having this problem right now but accept my Mac won't turn on
Alpha Goes Roar me to
WHAT HOW DID U TURN ON ITS NO WORK FOR ME
Lucarino what you need to do, when the screen turns black, press option, command and eject at the same time. this should put the mac to sleep, then press the keys again and it should wake the mac up, and the screen should be back, then lower your brightness so it doesn't happen as often
I've had this problem as well. I just got it to stop though. Here's what seems to have worked for me: It was either A. Switching to a wired keyboard or B. Blowing compressed air through the vent covers to better increase air flow to computer. To do the second one, you can just peel off the black glass screen (it's apparently only attached by magnets. Peel from top) and shoot the compressed air down through the ventilation holes. I don't know which fixed it, but now I'm at full brightness with no shutdown, when I previously could only run with ZERO brightness. Hope this helps someone else.
Tysm I wasn’t even reading this properly all I did was turn my brightness all the way down then a bit up again and it works fine now no shut down for the past 2-3 hours thanks dude 🙏🏾
It's got me too, First iMac I ever paid full price, for and it was perfect for 2 years, well almost perfect. I did see a video flicker ever now and then. Bought it in 6/2010. It's a 21.5 3.06ghz 4megs 1TB. First the DVD stopped working, then the hard rive died, worked off external, then screen went black, turned it off in disgust since I was a Mac Consultant and shoved it in a corner. You could get the screen to come back by pressing the power button in quickly and release while moving the mouse for awhile. Now it's just black with the fan running wide open. Can't even access it with remote access software. I used to love Apple the company, now I still like the products but a company should make right things they screw up. It's pretty cleat that since SO MANY people are having this issue it's a design flaw. But I've seen Apple do it before, just say, Oh Thats End User error.
Hi. Guys If it passes a 3D stress test like Heaven or Furmark and similar on Boot Camp and the stress test for the CPU. It's not the GPU. One just needs to adjust the fans, HD at 2200 rpm, the CPU at 2800. If it doesn't pass the 3D and CPU stress tests, that's the time to "reball" the GPU chip with torch or have it repaired. But try to adjust the fans first using smcFanControl for OS X and the Macs Fan Control for Windows. God bless. Rev. 21:4
SMC fan control is not recognised as a good tool by Apple. a technician once installed it on my laptop and the laptop died 3 days later
i had the exact same problem but this time when seconds it turns on the screen goes black
I have a late 2013 27" inch iMac. I left it for 2 days and it booted up. I removed "brightness slider" app in case it is malfunctioning
Having exact same problem with 2011 27" iMac. Took to the Apple Store and they found no problems with it. But next day at problem is back. Can not get to the login screen without it going black. 😡😡😋
let me know if you fix it cause it sounds like my problem.
I'm having this same issue, however the 2nd monitor that I have connected to my iMac NEVER goes black when this happens. Not sure of why.
bro if i connected black screen imac to tv so it show mirroring
I've had this same problem. I Think it is a heat related engineering issue related to the display software. When lowering the display brightness it occurs less frequently. I also installed SMC fan control and put the settings on that up to 3000 on all 3 fans. That runs a bit noisy but the issue occurs less often as the computer is kept cooler. I also think it helps to blow the dust out of the machine as all those tiny holes keep hot air in if they get clogged over time. To do this I simply slipped guitar picks to the edge under the screen then pull it away. It is held on by magnets and will come away easily when you edge the guitar picks around it. Then I undid the screws that release the video screen and just lifted it up enough to be able to blast it out with a hair dryer. That way you don't have to mess with any cable connectors. It's best to do this after the machine is cool and only for a few seconds each time as the hair dryer gets real hot and could effect components otherwise. Just give it a good blasting to clear those holes so it can breathe. Then, this part will sound odd, but by turning my screen up to full brightness I no longer have the problem. Yet when I come away from full and come down a few notches it still occurs intermittently. I can use command, option, eject to quickly get it going again and then I am able to lower the brightness to below halfway which once again reduces the heat energy and allows the screen to stay operations. The weird part is that it does work when on full brightness. Anyway, I hoe this helps somewhat.
Tomorow 9-12-15; I will take the LCD out of the iMac 24 inch, and put it in another iMac 24 inch that i have. If this continues, my guess is that the backlight is going bad on the mac..... #2 My second guess that the there is the Detachable video card (if one) needs to be reballed with heat and liquid (clean flux) with a good heat gun. REPASTE with thermal paste (artic sylver ) and maybe that will work.
14 years later my 20 inch version likes to flicker on very low brightnesses. But even half way seams to work fine. I think mine is due to its age of 14 years
I have the same problem,i press cmd alt and eject keys altogether,this re-sets the graphics adaptor and usually it brings the screen out of the stupid black screen
+Steve Biggins : Peace, Does this work for you what you stated? And do you agree with the rest, that it is Either a Logic board isue? Video board ? Or the BACK LIGHT? ;;;;Command(apple) = Control (windows ) ; ALT (WIN) = ALT(apple) ; F12(win) = EJECT button.... -Out
what do u mean eject keys altogether?
Its works for me...for now
Which ones plz help
inverter backlight problem
I'm having this problem now, I took it to get a good clean and a new fan fitted, it worked for a few weeks, but now it is back to going off again
wat voor imac is dit dan?
I'm having this exact problem on a refurbished iMac I had less than a week before it started doing this. Pressing the power button twice slowly brings it back, sometimes for half an hour, sometimes for one second. It just did it again repeatedly more than 30 times before I gave up and turned it off. Can no one give any straight answer about this problem? It seems wrong that this is such a common problem that Apple must be aware of and they are refusing to assist people. If it's a design flaw they should have a duty to assist.
I have almost same problem... but from startup the screen is black. The system runs good but the screen never shows.
Same
I have same problem, have you figured anything out yet?? Plz help
nope.. end up buying a laptop.i still got the mac in case i buy another one and just switch the hdd
Just bought the 27" for $50 and has the same exact issue. The seller had it diagnosed by mac technician and came back with as a bad video card. The seller understandably doesn't want to pay $500.+ for a new card…I just finished removing the card (after 3 hours) and will try the baking method.
lol, i just gave up and bought a lap top. but i keep the mac until i can extract the data from the HDD
Happens to me all the time in bootcamp. Took it and apple checked it saying the comp is perfect, that it's a windows problem and that there is nothing they can do u.u
In having that problem right now except it is hard to fix
I had exactly the same problem on a similar Imac. I changed the standby settings so that it never goes to sleep mode and the problem seems to be solved now. I guess with some particular settings, there is a conflict between different standby modes. Well, hope I was clear enough.
I had the same problem, I installed a utility that shows the temperature and not overheating? now my screen is black and no longer Revien. I accede to my mac with teamviewer or a screen on tunderbold
Try command and R at the same time.
What does it do??
Ivan, Did you have exactly the same issue? as on the video... because i have the same problem, but i can watch video, run heavy application and within an hour (or less) of work it turns black as on the video. This thing started happening when i installed java update 1 week ago.
Mother board issues
si por supuesto,algún problema con el mac?
hablas español ?
yes ,that's right.it was last year,but now the logic board died!
hi ivan, this problem totally solved with changing graphic card ? has not happened again?
I have black screen probs my self. But mine dosnt start up. But if i conect my mac to my lcd tv no problems and after an hour my screen comes on.
I got the same problem bro.. When im playing games in mac and bootcamp after a sec my screen shows checkered line..
How did you get them to fix it? I recently experienced the black screen while playing any game on it.
Logic Board fail (graphics card)
i send my imac to the customer center and they told me that was the graphics card trouble, so they change it .now all works ok.
Could it be the graphics card? You have enough time to load up iTunes or something and test to see if the processor is still running when the screen goes off, if the sound stops as well you have a processor problem. Reboot and load up Activity Monitor and observe the processor core activity graph, if you see one core flat line first, then later the screen shuts off, it would likely be a over heating issue, maybe the fan has packed up.