IMac display dark at start up

IMac display may be stuck in sleep. How can I get it to respond?

Reset the NVRAM/PRAM and Reset the SMC.
27" i7 iMac (Mid 2011) refurb, OS X Mavericks (10.9.4), ML & SL, G4 450 MP w/Leopard, 9.2.2

Similar Messages

Imac display - dark cloud flickers in corner

Hello. I bought a 24" intel based iMac March 2008. Today after about an hour of being on, the bottom right corner started going dark and cloudy - kind of looked like a bulb going out behind the screen. It strectched to being the whole bottom right quarter and the rest of the screen seemed to flicker but still stayed relatively bright. I've turned it off now but am rightly freaked out...I called apple and they said to take it to a repair shop but would like to know if there's anything I can do here before I take that step. Any advice?? I couldn't find anything like this in the forums.
THANK YOU!
b.-

The same thing happened to me this morning with an identical iMac in the same space on the screen. Anyone with ideas, I'm all ears.

Why does my iMac display go off when I am starting up or waking up my machine from sleep..

Why does my iMac display go off when I am starting up or waking up my machine from sleep..?
When my iMac goes to sleep I then later try to click the magic track pad or keyboard and it will usually then show the initial password entry login screen and then go off. The machine is still on but the display is black and will sometimes flash up the screen again if I press the magic track pad or keyboard but will then black out again..

Well, there are many different reasons why it does this. It might shut off due to power voltage problems, system overheats, or there is a System Problem. The reason it might be hard to boot up is because your power button might not work properly or your system hard drive is damaged.
<Email Edited by Host>

Some times my new iMacs display start flickring when I starts playing a game. I am very annoyed. I have bought it only 1 month ago. What can I do?

Some times my new iMacs display start flickring when I starts playing a game. I am very annoyed. I have bought it only 1 month ago. What can I do?

A flickering display sounds to me like a hardware problem. Or does this only happen with a specific game? Of course your machine is still under warrantee so you could take advantge of it if you have a local apple store.

Impressive iMac 24" Dark Spots

Sorry to repeat. But I don't understand why what I posted yesterday disappeared.
My story is long to write down. I hope any of you who got experience with dark spots/patterns on iMac screens can help me to look into the problem I appreciate your help.
The associated pictures of this post can be found here in my google album:
http://picasaweb.google.com/zhangchao/IMacDarkSpots?feat=directlink
I purchased my iMac 24 inch in July 2008. After using it for 2 months, I noticed some dark patterns started to appear on the machine’s 24 inch screen. I should have taken it to Apple back then if I wasn’t using it all the time.
These patterns become clearer if you set the background to white. A lot of iMac users have reported similar problems. Actually, if you google "iMac dark spot", you can find a lot of such posts. The patterns I got are very similar to what’s reported here in the very first picture here:
http://discussions.apple.com/thread.jspa?threadID=1915086&tstart=15
I contacted Apple two weeks ago when I finally got some time free. I was asked to go to the Apple Store here in Milwaukee’s Bayshore mall and left my machine there for 3 days for them to investigate. When I went to the store to pick up my Mac, I talked to the gentleman who did the repair and investigation work and a manager. They basically told me that I got the patterns because there was some weird “white substance” everywhere in my machine. The substance was circulated between the layers of glass cover and the LCD etc appearing to us as the dark spots. However, it’s easy to remove the stuff between the LCD and the glass cover but impossible to remove the stuff which got into the LCD.
They strongly suspect the white substance came from where I placed my machine (my living room indeed). They don’t think the “white substance” is hair or fiber. It’s like pure dust and very subtle. Since they believe the cause of the problem is environmental, they will not fix it for me under my warranty.
But I disagree and I think the white substance indeed comes from inside of the machine.
Overall, I think my apartment is pretty clean. The machine is always placed on a wooden table which I clean every week. There aren’t a lot of things around my iMac so it gets good air circulation.
My apartment is located in an apartment community. Hundreds of people live here. The community is not new (20+ years old) and is professionally maintained. I talked to the manager of the community and some of my neighbors, none of them have ever heard of anything similar.
In my apartment, I have never been able to observe the "white substance" anywhere aside from the iMac. I did some investigation into the case, placing some blue tape under the hole of the back of the iMac where air comes out. After doing that for over one week, the only place that I can observe any "white substance" is on the piece of blue tape. The pictures in the album will make everything clear. This makes it really hard for me to believe the problem is environmental. In addition to that, if the "white substance" is so subtle and so weird (as if the only purpose of its very existence is to get iMac into trouble. Other computers and electronic devices in my apartment are completely fine), how can so many people got similar dark patterns on their screens?
However, Apple doesn't take this as evidences that the problem is not environmental. Right now, I am gonna buy air purifiers and hire professional indoor air inspectors to help me to find where the trouble is.
I read several posts re "iMac dark spots" problems. Some lucky guys simply got their screens replaced by Apple and others were just left with no help.None of them actually gives detailed explanation of the cause of their problems. I notice most of reported problems happen to iMac 24 inch machines shipped in early and mid 2008.
If you have any insights, please let me know. I greatly appreciate it! Thanks!

Since you purchased your iMac in July of 2008, you are right on the edge of your one year limited warranty.
Go here https://selfsolve.apple.com/GetWarranty.do and see if you iMac is still within the one year limited warranty. You will need the serial number which is located... click the Apple Menu then click About This Mac. Where you see the Version number 10.5 click there twice. The serial number will be displayed there. If you can't see it there, open the System Profiler. (Applications/Utilities) Select Hardware on the left. The serial number is on the right.
If it were me, I'd take the iMac back to that Apple store and *ask to speak to a manager*. Tell them you are dissatisfied with the outcome of your first visit and want your iMac repaired.
Make sure and take in your original purchase receipt from when you purchased the iMac and any other pertinent paperwork.
*"They basically told me that I got the patterns because there was some weird “white substance” everywhere in my machine."*
I don't believe that.
This problem started within 2 months of using your iMac. It would take the force of an F1 tornado to get that much dust inside the monitor that fast.
If you still can't get that Apple store to repair your iMac, if you can, go to another Apple store OR find an Apple certified repair provider. Perhaps you know of a friend with a Mac that might be able to give you some recommendations for a place to take it. But make sure they are Apple certified.
Carolyn

IMac G5 tries to start and dies after spinning cog for a minute

iMac G5 tries to start and dies after spinning cog for a minute
I did this;
1. Insert the Mac OS X Install disc that came with your computer, then restart the computer while holding the C key.
2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)
Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.
3. Click the First Aid tab.
4. Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
5. Select your Mac OS X volume.
6. Click Repair. Disk Utility checks and repairs the disk.
the result was.
the 'permissions' are sometimes wrong, but they repair
the hard drive is either repaired or OK
the iMac will then restart and work fine and sometimes shut down and restart OK
after replacing the Hard Drive I actually thought I had fixed it and went to bed late but happy,
on waking in the morning, however I was not so happy it fired up and then died after dong -> apple logo -> spinning cog -> dead!!
I would be grateful for any help
Thanks
Pete

Hi Miriam,
Thanks yes,
here we go -- after running disc utilities it tells me directory OK and disk OK (or something like that) When I replaced the Hard Drive, I started 'fresh' erased/formatted the hard drive (new Seagate Barracuda 7200 500GB) and it has just got 'tiger' on it (and upgraded to whatever it is now I think I remember 4.11, I can't tell at the moment as I have got the back off) I didn't transfer any data I just took the old drive (Seagate 160GB) out and stuck the new one in.
I've just changed the battery (I didn't really think it would work, but I was still hopeful and I'd bought the battery anyway) I did the LED thing, the internal power button thing, and the resetting the SMU thing (with crossed fingers and bated breath) but -- so I'm thinking is it the power supply? I read some of Jim's weighty, but worthy tome and resolved to remove the power supply and have a look. On opening it up, it does look as though, one (at least) of the capacitors has 'blown' (by the way, just in case I sound like I know what I'm talking about, I don't of course, I'm just quoting Jim's words;-) I'd love to send you a picture of the inside of the power supply showing what I believe to be a 'blown' capacitator (and I'm going to try to send one to Jim as I think it might be useful to him and others. can I attach a photo in any way or would you like to send me your email address <Edited by Moderator>
Thanks
Pete
PS it's still 'weird' to me, why it starts and runs well, when started from tiger (or whatever) and then starts or restarts from the Hard Drive unless I leave it a few hours and come back and try to start it
again? wow it's late nearly 4.00am here in london UK.

Intel imac display glitch and involuntary restart

Just want to know if anyone else has experienced this specific problem, there are plenty of complaints about intel imac displays but I can't be bothered to sift through them all trying to find a match for my problem.
A couple of months ago I was watching a video in quicktime and noticed that my screen was glitching and flashing fragmented diagonal lines - like a commodore 64 loading type thing. Then the spinning-ball came up and a force quit didn't do anything so I had to force shut down. I started up and it occured again. Then the screen went blank/black, but still lit up, and restarted without me doing anything. It also got stuck during start up the second time this occured. I panicked and ran out to buy a 500GB external drive, backed up all of my work and then re-installed mac osx from disk, archive and install job. This seemed to sort it and for the following two months it seemed OK. No sign of any problems.
Since then I have updated from 10.4.7 to 10.4.10 (which I have suspicion that it screwed the firmware in my motu 828 firewire audio interface, costing me a £130 repair - but that's another painful story).
It happened again tonight (the screen thing, not the motu). And the ball came up and I couldn't do anything. Force shut down, restart - screen glitching again. Then I had 2 unexpected restarts, one getting stuck in startup. Then a successful startup but accompanied by the glitchy graphics, mainly red/pink pixellated diagonal lines flickering in and out. I ran a disk first aid - no problems. Did a disk permission repair. Shut down and ran a hardware test, the first few minutes of the test the screen was still at it but then stopped glitching, hardware test found no errors (it was an extended test too). Now I'm back on it and it's all OK.
Any suggestions/similar stories?
When it occured 2 months ago I had the original ram that came with the imac. Now I have 2x1GB sticks of crucial ram.

That's it! Well, that's what I have. Unfortunately, I don't know about the cause, but I don't ever recall having it prior to an update going back about a year ago. I recall an update, and that update being immediately followed by some sort of Apple Graphics something-or-other. I feel pretty certain that's when I first noticed this. I just had my LCD replaced for another reason, but I think you'll agree, it's not an LCD issue. In my case, browser activity, scrolling up or down in a page, seems to be the most common trigger. I've also seen "pieces" of the torn page, on the screen when minimizing the browser to the dock (usually Firefox, but I think I've seen it with Opera and Safari too). Is there a way to find update packages installed somewhere? I'd know it if I saw it, and I'd definitely try removing that suspect package/update.
Message was edited by: geekboy2000 - corrected OS

Apples update didn't work for me: Boot Camp: iMac displays a black screen during installation of Windows 7

Boot Camp: iMac displays a black screen during installation of Windows 7 - Apple Support
I have followed each of the steps listed in the link above with no success.
Prior to adding the extra drivers I was able to start the Windows install process up to reformatting the "Windows" Bootcamp drive. After that the computer would go through some instal processes and eventually restart. After the restart the screen would go black. The black screen lead me to the Apple Support link above dated March 5 2015. After going through steps listed in the link above, I get an error message stating that the D:\Sources\instal.win. file cannot be located. I am forced to restart the computer at that point and theWindows install process attempts to start again but always ends up at the same point.
Note: I am installing windows 7 Pro from a DVD. I scanned the AutoUnattend.xml file and noticed that it refers to "Windows 7 ULTIMATE" but not "Pro" or any others that I could see. (see below). Could that be part of the issue?
Any feedback would be greatly appreciated.
<cpi:offlineImage cpi:source="wim:d:/sources/install.wim#Windows 7 ULTIMATE" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
</unattend>
iMac (27-inch, Late 2009)
2.66 GHz Intel Core i5
16 GB 1067 MHz DDR3
ATI Radeon HD 4850 512 MB

Here is an over-simplified explanation of WIM and CLG files. Assume your DVD Media contains
W7- Ultimate
W7- Professional
W7- Home Premium
W7- Home Basic
WIM Files
File1
y
y
y
y
File2
y
y
y
y
File3
y
File4
y
y
File4
y
y
y
The File .wim will contains a compressed image which contains File [1...5].
The W7-Ultimate .clg will have 5 entries, with all set to 'Y'.
The W7-Professional .clg will have 5 entries, with 'Y','Y','N','Y','Y'.
The W7-Home Premium .clg will have 5 entries, with 'Y','Y','N','N','Y'.
The W7-Home Basic .clg file will have 5 entries, with 'Y','Y','N','N','N'.
This allows a single .wim Image file on the DVD media to be used to install any of the 5 flavors of Windows. When you enter your product key, the Installer knows what specific W7 variant you have the key for and will tell the WIM to extract the specific files the installer needs to be extracted.
The following line
<cpi:offlineImage cpi:source="wim:d:/sources/install.wim#Windows 7 ULTIMATE" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
is telling that a retail product key will be entered, which should go look for this specific .clg file (from the five you already have on disk). You can test if it will work for you by changing this line to the following
<cpi:offlineImage cpi:source="wim:d:/sources/install.wim#Windows 7 PROFESSIONAL" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
If it does not work, the other issue can be related to device discovery. Typically A: and B: device names are reserved for Floppy Drives. C: is your internal HDD.
D: can either point to the Optical drive, or the USB. The normal convention is that the removable media is named from Z: backwards. Y: and Z: are usually used for Network drives, so X: should be your USB. First try with the change to "Professional". If it does not work,

IMac display getting yellow when external display is attached?

Hi,
I have a problem with my IMac (27'' Mid 2010):
I have an external TV attached via MDP->DVI->HDMI cable. When I turn on the TV, the iMac recognizes it and the iMac display turns blue shortly, then the desktop returns and my TV is ready.
What I noticed: After the desktop returns, the iMac sometimes suddenly becomes "more yellow". Don't know exactly how to describe it, but I can clearly see how the desktop returns and then suddenly the imac display turns a little yellow, could also be that the display just gets a little darker (although the display brightness is the same as before). it's nothing that really disturbs me, and although I never saw the color return to normal it does (but I think only after rebooting the iMac)
anything on this? anyone else noticed that?
Message was edited by: nachdenki

Hi nachdenki
I've used both TV's and Monitors with my iMac over the years and that default iMac Profile has always looked yellow in comparison. Try one of those other sRGB, RGB Profiles or create a new Color Profile for the iMac's display.
http://www.computer-darkroom.com/colorsync-display/colorsync_1.htm
Dennis

Imac display flickerring

Im having a imac, its having a problem with the display..It used to flickker .. I got to know the solution for that, but i couldnt get how to fix it..
I just turn the imac upside down and started , works perfectly.. but when i turned it to normal position it used to flickker... I want to know how to fix the problem!!!!! Please HELP ME !!!!

Hi Jeff,
Thanks for visiting Apple Support Communities.
See this article for some information and tips that can help resolve the behavior you're seeing:
Mac OS X: Why your Mac might not sleep or stay in sleep mode
http://support.apple.com/kb/ht1776
Best,
Jeremy

27" imac display acting as two displays

Can seem to find the answer to this, results lead to howtos on a dual monitor setup.
I'd like to know if I get a 27" imac can I have the monitor act as a dual screen setup. Essentially, I would like my windows to load and act the way they do given my dual screen setup that I currently have with my macbook pro.
I know I can resize windows and get it to mimic a dual monitor setup, sort of, but I'm trying to avoid this every time I open something new.
Does anyone know if is this is something that I can do easily with expose and spaces?
Thanks

Welcome to the Apple Discussions!
If I understand your question correctly then yes, the iMac display can be toggled back and forth between the two computers with F2. When the iMac's display is being used by the PC it is in Target Display Mode. The issue is that the iMac can only use mini-DisplayPort input from an external video source. So you would need a PC with m-DP output or a very expensive converter to convert your PC's current video output to m-DP. Then you connect the converter to the iMac with a simple m-DP to m-DP cable. These converters which are fairly new start at about US$150.
Dah•veed

IMac went dark

Last week my iMac went dark (the screen) but the Power light on front was still on. I tried rebooting and there was no start-up chime and it would not come up. I disconnected all peripherals and still no joy. I reset the PRAM...no joy. I tried starting up on another disk, including a TechTool repair disk...again no luck.
I took it in to an authorized repair shop...and they found a bad RAM module. I have 2, 1Gig ram chips and one of them went bad. They removed it and everything is great...I do not even notice a slow down so far. But I did order a new one from Crucial ($24).
Anyway, just thought I would share this since this issue might happen to someone else. This is a 2006 Intel iMac, 20". I had no problems at all, and my 3 year warranty was up last May (2009). I was so happy it wasn't something more.

First try iMac SMC and PRAM reset, please do each of them 2x. If that does not work then try restarting in Safe Mode, this will clear some caches. You did not mention the version of OS X running on the machine, if you are running Snow Leopard then install the Snow Leopard disc in the SuperDrive and restart, when you hear the start up tone hold down the Option key and start from the SL disc and run Disk Utility and Repair Disk Permissions & Repair Disk.

How do you know the best iMac display size

how do you know the best iMac display size
Only on them fits in the screen window and that makes the font so tiny. The others are too wide or too tall. I usually view at 150 - 200% for vision issues.

You say it's better to do the Media Browser? I'm fairly new to movie, dvd and garage band. How would I go about using the Media Browser instead of straight to iDVD?
Select Your project - go up to Share - Share to Media Browser and as Large (Not HD)
In iDVD select a nice theme - click on Media button - click on Movie - Select Your movie.
NOW - Save as a DiskImage - and test this before burning DVDs - if this Plays OK then either burn the Image by using Disk Util tool (and set down burn-speed to x4) - or burn via iDVD (will take more time)
I want to keep as much quality as I can.
Then don't use iMovie'08 or 09 or 11 - as they all discard every second line resulting in less quality on the DVD. I use iMovie HD6 or FinalCut any version.
Also...I tried to split my project in iMovie...but couldn't find a way. I wound up just making a copy and then deleting out a handful of scenes from the copy...I still have the original at 4:12hrs. Is there a way in iMovie to split a project?
I would make a copy and cut away a bit from the end - calling this Part 1 and from start of the other copy Part 2.
OR - there are other programs that can squees in more to a DVD e.g. Roxio Toast™ - BUT this has two cons.
• It costs - to me it was well spent mony as it can so much more e.g. back engineer a DVD to an editable form
• Squeesing in more on a DVD - costs in QUALITY - and as You want as much as it can be - then 90 minuts portions encoded with Pro-Quality encoding and full quality interlasced material from a video-editor that delivers this is the way to get 100% of what DVDs can do.
DVD is as standard only SD-Video - HD not possibly. Then You need Blu-Ray. (also Roxio Toast™)
Yours Bengt W

Is it possible to turn off imac display while mirrored display plays video?

I've set up a new 21.5" imac for my parents use in their living room and have connected their 52" lcd tv to the imac as a mirrored display.
One issue that i can't find a solution to is to find a way to turn OFF the imac display when they're watching content on the lcd tv. If they want to watch a film from the imac out to the LCD TV, they want to dim the lights and watch it, but the imac display being on in the dark room is distracting.
Is their any way (3rd party software??) to turn off the imac display while still being able to have the mirrored display running?

You should actually NOT use mirroring, although it would work OK on the 21.5-inch iMac because the screen resolution is identical to 1080p HDTV.
In System Preferences Displays pane Arrangement tab, turn mirroring OFF. This makes the HDTV screen extend the iMac's Desktop. In the diagram on that pane, it shows how the two screen arranged. The edge where they touch is where you can move your mouse cursor from one screen to the other. You can move the two screen around in the diagram, to match how the iMac and HDTV are located in the real world.
In System Preferences Displays pane Display tab, there will be a window for each screen. The 21.5-inch iMac's screen should be set to 1920x1080. The HDTV's screen should be set to 1920x1080 also, if it is a "1080p" HDTV.
To watch video content on the HDTV, first show the video playing in a window. Drag the window to the HDTV screen so that it is completely on that screen. Give the full screen command (usually Command-F). The video will play in full screen mode on the HDTV screen. In most video playing applications, such as DVD Player, QuickTime Player, iTunes, etc., the other screen (the iMac's screen in this case) will go black. It's not OFF, but it will display black.
Note: Some video playing apps have a preference setting for which screen gets the full screen. When playing video content in a browser window (such as YouTube or Hulu), when you go to full screen mode by clicking the +full screen+ button, the other screen will not go black.
As far as I know, there is no way to turn off the iMac display, even with mirroring turned OFF.

I5 27" imac display doesn't turn on

Hi,
This issue just cropped up for me this morning. When I go to turn on my recently purchased (Feb 2011) core i5 27" iMac, the screen doesn't turn on. Instead, it remains black until I hit the power button again, after which it will usually come to life. It sometimes goes black again without any warning. I can usually get the screen to come back to life if I hit the power button. However, I have an older 24" cinema display hooked up as a second monitor, and it always comes to life when I start up, and never goes black like the iMac display. Anyone else having this problem? Are there any known/recommended solutions?
Thanks!

Reset the SMC > Intel-based Macs: Resetting the System Management Controller (SMC)
and zap the PRAM > Resetting your Mac's PRAM and NVRAM
Then if that doesn't help, contact Apple Support or your Local Apple Service Provider. > Apple - Support - iMac - Service FAQ
Dennis

IMac display dark at start up

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