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모델 A1312 / Mid 2011 / 2.7 & 3.1 GHz Core i5 or 3.4 GHz Core i7 Processor, ID iMac12,2

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27" iMac doesn't boot past white screen, not-responsive

Yesterday, I was working in Autodesk Maya, and suddenly whole screen went black, so I did a hardware reset, by holding down the power button.

After that the iMac doesn't boot properly. It does the chime sound, then the apple logo with indicator and then just goes to a white screen. The keyboard doesn't work as caps-lock light wont come on.

I have tried the following:

  • RAM reset (Cmd+Opt+P+R)
  • SMC reset (unplugged power source for 2-3 hrs, held down power button for 10 sec)
  • Removed ram cards and powered up, it did the SOS beep with 5 second intervals, so I'm guessing logic board is fine
  • Holding down Option key during startup brings up the disk selector (I have 2 partitions one with Lion and one with Mountain Lion) neither boots up.
  • Tried booting from an external Mountain Lion Install USB drive, it shows up in Disk Selector, am able to select it, but then it stops at white screen
  • Ran a thorough Apple Hardware Test off the internet through ethernet cable, took 1:45 hours and it showed no errors
  • Tried to run through Mountain Lion Recovery Disk, same white screen
  • Entered sIngle user mode (Cmd+S) and ran fsck -fy on boot disk, it gave a few minor errors, so I repeated fsck -fy a few times until it no longer gave errors, still doesn't get past white screen. I'm able to browse the HDD in single user mode using the shell. Then did "exit" and also "reboot" commands, both ended in white screen.

I've looked around and found several guides dealing with this exact problem, but as you can see from the elaborate list above, none of those remedies have worked for me.

Any help is greatly appreciated, I'm on a tight deadline to finish this animation project and this is the only machine I have access to at the moment.

I don't have Apple care nor warranty and there's no Apple store/Genius Bar nearby.

답변되었습니다! 답변 보기 저도 같은 문제를 겪고 있습니다

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댓글 18개

Sorry, don't have a solution, but I am experiencing exactly the same problem. I do have a spare SSD drive with Mountain Lion installed as a secondary boot disk and tried Target Disk Mode via Thunderbolt, but again, I didn't get past the white screen.

Plugged the MacBook Pro in to the iMac using Thunderbolt and Target Disk Mode, and Disk Utility reported that everything on the iMac was fine.

Unhooked all the peripherals in case of a dodgy cable or peripheral and restarted, but no luck either.

Disk capacity isn't an issue, as I have some .95 TB remaining on the main disk. Fragmentation might be, but it'll take hours and hours using iDefrag.

I'm stumped!


Wow! That's great news. I sent my iMac off today to Apple Authorised Service Centre to have the video card replaced, and it looks like I'm going to be refunded the £309.xx pennies to repair it!

Well done Apple for doing the right thing, I say, and a heartfelt thanks for posting the link. I had no idea this was a known issue, so I really appreciate it.


Same Problem Here. 27" iMac 2011. No boot to USB or CD. Finally I just changed the Hard Drive which was a Seagate Barracuda 7200.12 1TB. These are know to have firmware issues. There is an update you can do if you go to the seagate website and download an iso and burn to CD. I suggest doing this if you know you have this Hard drive before the problem arises. After I switched HD's everything is back to normal. I think the HD is somehow grounding out the mother board. Glad I caught it before serious damage occurred. I wonder if I can file suit.

Had an unresponsive iMac 27 with frozen white screen at startup. After multiple unsuccessful attempts, called Apple support and they directed me to a few steps which didn't work, then to a COMM+R and reinstall the OS. After this, computer started, very sluggish. I have an airport where I've been backing up my computer for a long time. I restored to a few days ago, and after that basically back to normal. Good luck to all...

iMac 27", white screen.

1. Tried command + R = white screen > little apple logo > wheel > white screen.

2. Tried power on + shift key = white screen > apple logo > white screen.

3. Finally the following worked! "command + S" = terminal, where I typed the commands posted above for this, reboot .... restarted with power on + option + N. This solved my white screen problem. System restarted, Finder, Desktop, etc , etc, Thanks so much!!!!

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선택된 해법

Apparently this is a graphics card problem, Apple recalled it, see http://support.apple.com/kb/TS5167 I got mine replaced by Apple for free. Good luck!

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댓글 5개:

Hi, I have the same problem. Is this white screen problem from the graphics card or is it a firmware problem? I haven't tried fixing it myself such as : RAM reset (Cmd+Opt+P+R)

SMC reset (unplugged power source for 2-3 hrs, held down power button for 10 sec)…

Since I bought mine in July 2011 and the graphics card is suppose to have a warranty for 3 years so Apple should fix it for free right ?

Thanks for the advise !

You'll need to tai to Apple there is a recall on some systems. Check with them if yours is one of them. Check out the link in Ganesh Rao's answer above.

had this happen to me twice on two different iMac, its most definitely a Graphics card issue.

Do you have a name to go with that graphics card that’s been recalled? The link you provided no longer works, and I’m told the iMac I’m working on worked just recently so I want to make sure before stripping the thing down to get to the card itself.

This also happened to me I don’t know how to fix it I was doing work and all the sudden me screen glitches really bad and goes white I tried turning it off and back on but nothing would work I tried so many different strategies but nothing is working

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I had the same problem on my iMac dual-core 3.06gHz. Stupidly I put in a firmware password and forgot it and I had recently blocked anybody accessing my CD drives etc. Even I was blocked. Therefore I couldn't wipe the hard drive and reload OSX. I got the blank white screen.

This method got my iMac back. To do this you need to alter your RAM configuration first by adding or removing memory. This forces the PRAM to take action. You will still need enough RAM to run the machine of course.

1) After changing your RAM either up or down.

2) Using a wired keyboard, start computer with keys COMMAND-OPTION-P-R pressed in.

You MUST use the COMMAND-OPTION keys on the RIGHT side of the keyboard.

3) Let the machine boot THREE times (mouse lights up on each boot cycle, turn it over to see)

4) After the THIRD or FOURTH boot cycle hold the OPTION key down ONLY.

5) A BOOT MENU should appear. I cannot remember if I hit EJECT on the boot menu or on the keyboard. Try each if it doesn't work first time.

You can access your CD drive now, put in your BOOT CD (OSX disk).

Reboot into Single User mode and reload your OSX system.

At step (5) You may not have to reload your system files, just set up your PRAM.

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댓글 6개:

Using the COMMAND-OPTION keys on the RIGHT side of the keyboard is imperative else this method will not work. It took me ages to find this solution on the Web.

John - Love your exuberance in answering questions, only problem here is this is a very old question and has long since been answered with the correct answer - Accepted Answer. Look for ones that don't haven any answers. Hope to see more postings!

John, have an iMac and had the white deadly screen yesterday. I tried all sorts of ways to resolve the issue.

I was able to restart the computer on SAFE MODE, but, if i try to log on my computer through the main admin the screen will flash once and it prompts me to type in my password.

Since i have guest user on my PC i was able to login using that account just fine.

What can i do from here in order to recover my main access to my computer and files using my main admin access?

Thanks to all your helps!

Alex P

Where do you get a Boot CD?

Should have come with the Mac. If not friends, or hunt online for a d/l.

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Same problem only my solution was to press on D while holding the power button until apple logo came up then the bar showing it was loading something. Afterward it worked fine.

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댓글 8개:

This worked for me! It had me puzzled for days! Kept swapping in new drives and they worked for a day then boom back to the same problem!

The 1st problem was it wasnt booting and kept going to a white screen, then I tried to boot from an external and I got a blue screen. Reloaded software on using thunderbolt and I rebooted with the same problem but it was going into a loop of boot, apple logo, loading line, white screen and reboot.

I rebooted holding D and it fixed it! Thankyou

Not really sure what holding the D on start up does, but it worked for me also. I been having problems starting my iMac, keep getting the white screen with the Apple logo. If I play with it long enough, eventually it will start up. At one point, I got a black screen with some messages that said something about bad memory, I showed it to the tech person at work, and he suggested I try to replace the memory cards, which I did. Still got the white screen after replacement. Finally came across this post and gave it a try, and it started up. Don't know if it'll continue to work as I'm afraid to shut it down right now, but it did work for now! Thanks!


Your iMac still works? Mine can't get pass the white Screen. Pressing down D starts some Hardware Test over Internet. Unfortunately after finish, the white screen shows again after Reboot.

Red 5.

Thanks for this! I am not good at this stuff, but the D key boot ran the diagnostics, and it reported the hardware was fine. Then it booted up fine on restart. Couldn't believe something finally worked.

This is a bit weird! :)

Though it just runs a test which should change nothing in the machine, it worked for me too! I noticed that the computer got quite hot during the extended test; I wonder if this created a kind of reflow of the graphic card... :-D


Well... it worked for 2 restarts... :-/

Now the extended hardware test neither finds a problem nor makes the iMac starting again. I still have a little hope that it is the hard disk, but it looks pretty much like the graphic card... -__-

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Can you boot from an external HD or flash drive?

If you can you will likely need to run Apples' Disk Utility to straighten things up. I would strongly recommend clearing out some of the stuff you have on your disk as you likely ran out of space and/or have a highly fragmented HD. Try using Drive Genius or other good defragmenter app to defrag the HD.

If you can't boot with an external drive then your problem is not HD/OS related.

But given the fact you can get the system to run and access the HD in single user mode I suspect its the HD that just needs attention.

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Thanks for the quick response. I've tried to boot from a Mountain Lion Install USB drive, but that too doesn't get past the white screen. I will try using the Target Mode and see if I can run Disk Utility through another machine.

That should do it! Also why don't you copy off your important stuff first just to be safe here.

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Thx for writing this article - had the same problems. And actually repaired earliere iMacs 27. So have a bit of insight in the tech. But was getting grey hairs over this one, and wen't through all possible scenarios (as you) then after two days found this o/ :)

Thanks again, will contact Apple tomorrow.

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i have got same issue and the problem is Graphic card. The solution have simple if u have a little electronic skills. teardown imac and remove the graphic card. and also remove gpu coller. your graphic card must be like this picture of gpu after that u must be very carefull this proses. first u clean gently with alcohol and toothbrush. after that u bake in oven like this video after that your graphic card work.

this solution is riskly and get your own risk.

your gpu has died also, maybe u can take it life back again

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댓글 1개:

Aza - We've given up trying to salvage graphic boards as while you maybe able to get it working it won't last, sorry ;-{ We did 5 systems and all five ended up dead in a matter of weeks. Best to just bite the bullet here and replace the card with a new unit. Besides, given the amount of work just to get it out its just not with doing it over and over again.

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Ok… I had the white screen… and I tried everything… all the command this command that.. option this option that… and finally Command + S brought up a bunch of computer garble .. so I tried that fsck-fy and it said Bad Command … so I was like.. I don’t want to “exit”… so.. I typed “reboot” and wa-la the sum of a dog finally rebooted and I am back in business… unbelievable

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I tried the above also Jay, but different, i try the command+s . o problem loads of white scripted code and text then, i try fsck-fy no joy did nothing, so thought what the !&&*, i'll just reboot then by typing that in, and then it flashed did something upon loading and now i got it back online again, only i am going to try to delete the partition and refresh the os x instead obviously corrupted or something, then i will buy 32gn ram and upgrade memory and change the drive from a simple one to a 1tb ssd drive sorted, will update as and when i get this done....

Thanks for the info though :-)

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Mine had this issue and it turned out to be a SMART failure on the hard drive.

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Or you could just turn it over to apple and get its replaced for free :) https://support.apple.com/en-us/HT203787

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Hi there, I have a second hand iMac 27" but don't have any other data than that, I bought it from a company that went bust. I now have the white screen of death. Is there any way I can discover if my iMac is one of the 'problem' iMac's covered by the recall?

If you look at the bottom of the foot stand you'll find the serial number with it you can find out what year your system was made and what options it has but plugging in the serial number into this web site: EveryMac then review the Apple T/N link above HT203787 is it the same graphics card? If so make an appointment with the Apple Store to have it fixed under the extended warranty. Even if it isn't under extended warranty I would still bring it in Apple tends to have other recalls that are not documented that might be your issue here as well.

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I have a similar issue, with my imac 27" EMC 2546 from late 2012.

The fusion drive was using the 3TB seagate baracuda that was under the apple recall, and it failed.

However when it was failing and I was trying to boot from various other means, as from a usb stick, external drive or dvd, and it was only booting barely about 1/3rd of the way and stalling.

Now with the whole fusion drive out (HDD&SDD) and a new blank seagate non apple drive in place (a 4TB), I get the same thing, and using a large number of methods to boot:

- external HD (yosemite)

- external HD in recovery mode (yosemite)

- external HD in safe mode (yosemite)

- external DVD installer disk (10.6 and 10.8)

- off the net (netboot)

- USB stick (10.6, 10.8 and 10.10)

- USB stick in safe mode

I can get it to boot in single user mode in any case, but nothing beyond that.

I tried installing linux on that blank new drive and that worked fine and linux runs great on it.

Running AHT, off the net, because I can't get that to run from anything else, only shows the expected error from the missing temperature sensor on the hard drive, because it's a genuine seagate non apple. So I expect all the system tests show nothing wrong with the machine, unless the AHT stops on the sensor error and doesn't finish the remaining tests, which I would assume wouldn't be the case.

Resetting the pram hasn't done anything, despite having done it many times.

The SMC has been reste many times, at first by having the machine go to the local apple authorized store for the hard drive recall (I got the machine back because I didn't want them to keep the original drive with my data on it).

Everything seems to point to a healthy machine, although the missing firmware on the seagate drive causes the AHT error on the sensor, it runs linux just fine and it seems fine only until osx boots up to about 30% and stalls there.

The only thing I could not try is to put it in target mode, because it has thunderbolt and not firewire, while I have an older laptop with firewire and not thunderbolt. I plan to locate a thunderbolt cable and ask someone I know to allow me to link up with their imac to see what I can do with the drive in that imac, but I suspect even if I managed to put a functional system on that drive, it won't boot any further that in any other boot method.

So what else could it be then???? I'm out of ideas.

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댓글 5개:

Any update on this one? I'm in the same boat now and think it's the video board (although it could be the logic board.) Since there is a known issue with the AMD (ATI) GPUs, that's my guess. I'll probably order one (new) and with the 512MB onboard vs. the 1GB or 2GB as they run hot and would likely be more prone to failing again...

I replaced with the 512MB video board and all is well. My old video card would completely pass during ASD testing, but would not boot to login screen (only half way through progress bar then black/grey screen.) Took quite a while to diagnose. Not very hard to open up this system once you've walked through it a few times.

Hi didier, have you found a solutions for this problem. i have exact same problem with my iMac EMC 2546, LATE 2012 model, I did all you mentioned, and nothing fixed the problem. please share your solutions if you have any.


No, the only local apple approved retailer declared the whole motherboard to be defective and to be changed, obviously for a small fortune. And since at the same time I also had a deadly issue with the internal hard drive (supposedly under warranty), all this with the data recovery which they wanted to farm out and the exceedingly expensive drive swap cost, what they were asking to repair that thing was more than buying a new one. Classic apple behavior. They're bandits!!

So I got back my machine as it was and got myself an other from ebay for far less than the cost they wanted to charge me and I worked my way through getting my own data, and put this all back together with a new drive from ebay, which also cost a small fraction of what they wanted.

Basically, I didn't pay them anything more than the estimate, since they wouldn't release my machine to me without charging something.

I kept that machine, just in case I can fit it somehow.

I'm quite certain this issue, which many have encountered, could be much more easily fixed, and for far cheaper than what apple wants to charge for this.

It's quite typical apple, to charge a huge amount for something minor, so they can just scrap the old and sell a brand new one, or make a killing on the fix. Either way, they always win and cash in like bandits. NOT GOOD!!!

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hey! well there's many different solutions and I had a problem related but I couldn't figure it out so I went to this tech store for apple computers only and it's not expensive and they will take any challenge and they will do it right then and there.

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I'd turn off FileVault if enabled when troubleshooting this!

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귀하의 답변을 추가하세요

Ganesh Rao 님은 대단히 고마워 할 것입니다.
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