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OSX Lion + 2011 iMac 27'' + Video = Freeze

Hello.


Got a brand new 27'' iMac, installed Lion. The machine freezes randomly when starting to play videos, either on Youtube, Quicktime, iTunes.


When it freezes, the mouse still works, but the machine doesn't respond to any command, requiring me to hit the power button and restart the computer.


Searched on kernel.log and system.log, and found no crash/error/message.


Anyone suffering from the same problem? The machine is pretty solid, been running some OpenCL kernels too and they are ok. It's only video decoding (possible on the GPU) that seems to freeze randomly.

iMac, Mac OS X (10.7)

Posted on Jul 21, 2011 6:46 AM

Reply
2,021 replies

Jul 20, 2012 2:21 AM in response to Gerard H

I fixed my "wheel of death" problem that had plagued my MacBook Pro for months by deleting two third party anti-virus programs that I had foolishly installed. Now what I thought was a hardware problem has been fixed by a simple software solution. Instead of rebooting a frozen laptop up to 10 times a day I now reboot once a week.


Try deleting any third party anti-virus programs and start trusting Apple's regular security upgrades.

Jul 22, 2012 2:39 AM in response to rubenlx

Hello all.


I also have this problem on my late 2010 27" iMac.

Some more info about my setup.

All USB slots used

FireWire 800 port also used.

Upgraded from original 4gb ram to non apple original ram 16gb. Corsair memory. Installed them in September 2011

Installed lion the same week it came out last year. Around the 7th of July.


I Yesterday had this problem and I filmed the computer making **** of a noise. My 6-year old daughter started crying since she were the one using the computer at the time.

All she were doing was playing nickelodeon games on the web using safari. I guess they have flash content but I am not sure.


http://www.youtube.com/watch?v=CqeTWf2h8mU&list=FLGNA8HkDdqt4vQGocliNjmQ&feature =mh_lolz



Anyway, I would like to know if you have the similar problem. It does not sound like coming from the harddrive. More like some sound coming from the sound card.

I have read that iMac 27" have problem with 16gb so I'm thinking of removing one slot. have not done this yet though.

I also read there where some issues with external sound cards via FireWire so I sold my card and replaced with a new USB device instead. So far nothing has changed....


I really love my Mac and would like to have this solved. There must be some way.

Jul 22, 2012 4:47 AM in response to a94andwi

I was thinking I should try this once again. So I gave the task to my two daughters to go to the same nickelodeon webpage and start the same game again.


It only took minutes until this happend again.

I listened more carefully to the sound and where it came from. It sounded like it came from the bottom left corner of the imac.

I checked some tear down pictures of the imac I found on google. If I understand correctly it is the area where the logic board is placed.


I found also that a new logic board costs abour 1400 us$. :-(


So right now I think it might be a logic board issue but at the same time I wonders if it could be connected to safari or flash.


Not happy!

Jul 22, 2012 10:43 AM in response to rubenlx

My machine is 27" iMac , July 2011 (1 year and a week old) , It started with some freezing but afterword, worked again normally. Then 3 days ago, it stopped working and I tried again many times to have it start. After having the grey apple and spinning wheel at power on, it kept having a white screen whatever I try, safe mode( holding shift key), recovery mode (holding option key), starting from DVD (holding C key)...

They I left it a few hours without trying anything, then 2 days ago, it started to work normally for 10 mn and then stopped again and did not work since.

Could it be a video graphic card problem ? The strange thing is that when I start in recovery, I get HDD and disk graphism but I do not know if it is someting who calls graphic card functions.

Power supply seems OK, but I wonder if I am facing some mother board, HDD or something else trouble.

If someone has an idea of what kind of test I could do to diagnose the issue, any idea is welcome.

Jul 22, 2012 12:12 PM in response to rubenlx

I pass for the same issue, check my YouTube channel I put same videos for the issue in my new iMac, that videos apple support watch. I changed the iMac two times I call so many time to apple care, but no solution after that I fix for my selft right know I have 4 months with not issues......


http://www.youtube.com/user/stripios


The first step is download the lion to a USB drive to do bootable.

The solution is easy wipe all the hard drive, delete everything hd recovery and all the partition, important do the backup but DON'T RESTORE THE IMAC FROM THAT BACKUP JUST MOVE MANUALLY THE FILES YOU USED IF YOU RESTORE FROM THE BACKUP SOME TIMES THE ISSUE COMEBACK.



After reinstall the lion from the USB the same way when you reinstall lion from hd recovery.

Press OPTION KEY AT THE BOOTING TIME AND INSTALL FROM USB.


Follow this link for detail process:



https://discussions.apple.com/thread/3969205?answerId=18447578022#18447578022

Apple engeniers call about my fix because is worked


I hope help some one:)

Jul 22, 2012 12:21 PM in response to rubenlx

I pass for the same issue, check my YouTube channel I put same videos for the issue in my new iMac, that videos apple support watch. I changed the iMac two times I call so many time to apple care, but no solution after that I fix for my selft right know I have 4 months with not issues......


http://www.youtube.com/user/stripios


The first step is download the lion to a USB drive to do bootable.

The solution is easy wipe all the hard drive, delete everything hd recovery and all the partition, important do the backup but DON'T RESTORE THE IMAC FROM THAT BACKUP JUST MOVE MANUALLY THE FILES YOU USED IF YOU RESTORE FROM THE BACKUP SOME TIMES THE ISSUE COMEBACK.



After reinstall the lion from the USB the same way when you reinstall lion from hd recovery.

Press OPTION KEY AT THE BOOTING TIME AND INSTALL FROM USB.


Follow this link for detail process:



https://discussions.apple.com/thread/3969205?answerId=18447578022#18447578022

Apple engeniers call about my fix because is worked


I hope help some one:)

Jul 26, 2012 5:23 AM in response to rubenlx

So took my late 2011 iMac 27" (bought in December) to the Genius bar after I couldn't even keep it alive enough to set the appointment online or even switch users. The Ctrl-Option-Eject sometimes helped but not every time. And it seemed like if the machine was waking up cold it lasted a little longer.


And wouldn't you know, when I got there it didn't fail.


And they said that the 3rd thing on their checklist is resetting the SMU-System Management Unit—and that is done by removing the power supply for at least 10 minutes, which obviously happened for me to take it to the Genius Bar.


And it's been working just fine for 36 hours now.


So to all of you with the black screen problem, I highly recommend trying unplugging it and giving it a good rest so it can clear itself out, and see what happens!!

Jul 26, 2012 6:16 AM in response to BulaRae

I thought the same thing (about the SMU reset) We had big storms knock power out at our office for at least 10 hrs over the last weekend. The backups only kept them breathing for 15 minutes, until all shut down. When power was restored the next afternoon, the machine seemed to be over its blackouts for a day or two, but since then the issue is back.


It Also seems that it only does it in the morning after a cold start, once its warmed up, it rarely ever blacks out. Seems like a bad connection somewhere since once the machine gets warmed up, components get hot it never blacks out.

Jul 26, 2012 6:36 AM in response to BulaRae

I think I solved my issue yesterday. After I had my iMac checked at Genius Bar last sunday, they decided to replace my HDD free of charge but I had to manage my backup. So, last tuesday I had my computer back but after 10 mn, same stuff, freezing and more , screen flashind at high speed and then crashed. I went back to Genius Bar but after a serie of tests everything was checked OK with the hardware.

So, I took my iMac back again home and again it crashed after a short time. After all my reading I decided then to uninstall flash player and see what happens.

Miracle! All was working great and stable! But of course no more video from youtube or anything else.

So, I tried to reinstall flash player 11 from Adobe site. It works for me. All is working great (like new) and very stable, and now video is OK and no more freezing or picture distorsion.

Hope my experience can help.

OSX Lion + 2011 iMac 27'' + Video = Freeze

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