Imac display issues following Yosemite upgrade

In reply to Andreasgr and others:

I thought that this problem was related to Yosemite but I was also told to try various "solutions" which have included

1. check box to "reduce transparency" in system preferences/Accessiblity

2. turn of Safari extensions

3. uninstall memory hogs like Sophos and CrashPlan

4. try I different Internet browser like Firefox or Google Chrome

5. insufficient user memory (I have 16 GB RAM)

I did all of the above and thought I was free of this problem until it recurred a few days later. This morning, after I had to hard boot restart my computer I restarted the computer in 10.68, my favorite OS. 10.68 was the OS that came on my iMac 27 using a solid state drive. Immediately upon start up I had the pixelation. I have never had this before on start up. I would conclude as Andreasgr that this is not a Yosemite issue. In the past AppleCare senior tech thought it was because I was pushing the graphics card with too little free user memory. But this problem has occurred when I had as much as 12 GB of free RAM.

So I hard rebooted back in 10.10.2. I did see pixelation shortly after restart. I thought this was going to be the end of my computer use. I noted that usually going to Safari seemed related to this problem. I immediately exited out of Safari. I looked to see what programs I was running in my dock and I was only running Acrobat Pro XI and an app called PathFinder, the latter is far better than Finder. I exited out of PathFinder. The pixelations disappeared. I right now have Safari open, along with Word for the Mac and also Mail, TextExpander and an app called EndNote. I also have SpamSieve running. BTW, I did do a graphics card analysis using Novabench from the App store. That test was normal.

I wonder if this problem we are having is not due to an app that is negatively interacting with the OS. I wonder if starting up in another mode like single user mode or even safe mode could be helpful to sort this out.

I'm having a graphics issue as well. Initially I was going through the stalling grey screen, and it turns out that I had bad RAM (according to Apple Hardware Tests). So I removed the bad RAM, and put in the original RAM the iMac came with. My iMac now boots fine, but now I'm seeing artifacts, and now horizontal red lines (occurred after the below screenshot was taken). However the display is perfectly fine in Safe Mode.

The Menu Bar is an example. I click on the Apple for the drop down menu, but the drop down isn't seen, but I can still click on the options as if the drop down is seen.

I've tried resetting the PRAM, and toggled with the colors and display resolutions, and no luck. 😟

Please, help!

UPDATE: I forgot to mention that I did a clean install of OS X 10.10.3 via App Store and that didn't help.

+1 on mid 2010 iMac with NO previous display issues - install Yosemite, and suddenly I'm seeing HUGE screen corruption and pixelation..

I'm upset because after MUCH research it appears we are all shafted.. Back to mountain lion for me..

Hi all,

What is now the latest thinking on the "colored squares"-syndrome ? I experience this issue now for nearly 1 year on my 2011 iMac... at that time running Mavericks. Bringing the troublesome patient to an authorized Apple repair-center didn't reveal the root-cause: it disappeared for some months; but recently came back, heavier than ever. Completely desperate, I yesterday installed a fresh Yosemite-copy, after formatting my drive: so no arguments anymore on non-Apple software causing this. Guess what: the problem only intensified...

I tried all possible workaround from this and the numerous other posts: none of them actually worked. Closing down soem application like e.g. Mail (see screenshot) caused a complete freeze...

Is the only solution replacing the GPU (I don't really feel of 'baking' the GPU in the GPU myself in an oven as some suggest...) ?

Please advice,

Peter

Ok, so I'm NOT insane! This problem started creeping up for me in late-Mavericks. It was initially just a sleep problem -- when the computer would sleep, it would show the screen corruption and freeze. Or, I'd periodically have a light smattering of the 'odd characters".

I was starting to have more and more problems, the corruption creeping in during app use, so I updated to Yosemite. MORE problems, immediately. Not just annoying, but affecting usability. So I did a clean install of Yosemite. STILL mondo problems. I was searching high and low, and couldn't find anything... until I described the issue differently. Screen CORRUPTION was the key phrase. Whew!

I've read through this entire thread, and applied all the potential fixes. Things are good now -- but as we all know, this issue can come back after 5, 60 or 1000 minutes. Ugh!

So -- I feel better that it's not just me. BUT... also frustrated that this is so clearly ANY ISSUE but there seems to be no solution. *sigh*

My rig:

- Late 2011 MacBook Pro 15"

- AMD Radeon HD 6750M 512 MB graphics card

Amy

Exactly the problem! This fixed it. Thanks!

jackiepanpan wrote:

I turned on "Reduce transparency" in System Preferences > Accessibility > Display and that seems to have fixed the issue for me.

This did it for my Mom's 11,1 model iMac with a Radeon HD4850 - I did a clean instal of El Capitan and after a week her iMac screen started to flicker 😟 I started searching around and stumbled on this thread, and your post reminded me of this very useful setting. Not only did it stop the screen flicker, but now the menus and window titles are easier to read again! Thanks for the reminder. Apple and video cards have been a real problem for a while now - my late 2008 MacBook Pro is the poster child of bad video chips - it had two logic boards replaced under warranty and it's once again dead. I haven't gotten around to doing the oven bake trick as I think it's probably time to upgrade to an Air anyway.

I have a Mid 2011, 21.5" iMac. 2.5Ghz i5, 16GB 1333 DDR3 ram, Graphics card listed as AMD Radeon, HD 6750M 512MB.

Over the past couple months, I have had display problems such as pink/grey checkers and a few other strange anomalies, have led to requiring a reboot. Problem returned over and over.

I have run the Diagnostic test several times, Nada. All clear.

Turned off Transparency, I've been a week clear of any problems at all, and I even dared to push to where I thought I could induce the issue previously.

Could it be that this above step is merely reducing the load on the graphics card, eliminating the problem temporarily?

I've got the problem with a week old MacBook Pro (Retina, 15-inch) running El Capitan 10.11.2, but haven't had it with my previous 17" Pro. Although 78 of us have the problem, no one's solved it.

So I've been havingthe same problem with my mid 2011 iMac 27" for the last 6 months. Started off very infrequently in the beginning and has gotten progressively worse. To the point that a few days ago the pixelation was happening all the time and got so bad the computer would freeze and I'd have to re-start it a few times a day. I've been on the forums looking for advice etc and someone suggested connecting an external monitor to see if it would pixelate or not. So I did and there was no pixelation on it. And here's the kicker - my iMac has stopped pixelating or freezing. Going strong for 2 days now. Very strange.

Hi Linc Davis

I was hoping you could help me I've been having trouble with my iMac and I ran the diagnostic test that you posted on Oct 17, 2014 I have the results and i was hoping you could see if there ok, I'm not very good with computers and I think I could have downloaded something bad on my mac it has been freezing and display has been pixilating and my mouse jumps around quiet a lot also when moving or closing a window it overlaps and multiplies like pages in a book. Thanks so much for any advice I really appreciate your input and time you give the best advice

regards Mel

Start time: 17:58:31 01/16/16

Model Identifier: iMac12,1

System Version: OS X 10.10.5 (14F1509)

Kernel Version: Darwin 14.5.0

Time since boot: 7:23

SATA

WDC WD5000AAKS-402AA0

USB

External USB 3.0 (Toshiba America Info. Systems, Inc.)

Diagnostic reports

2016-01-16 UserAccountUpdater crash

2016-01-16 mdworker crash

Log

Jan 15 22:51:49 ** GPU Hardware VM is disabled (multispace: disabled, page table updates with DMA: disabled)

Jan 16 00:07:47 jnl: disk1s2: do_jnl_io: strategy err 0x6

Jan 16 00:07:47 jnl: disk1s2: write_journal_header: error writing the journal header!

Jan 16 00:07:47 jnl: disk1s2: close: journal 0xffffff8036d6ec20, is invalid. aborting outstanding transactions

Jan 16 00:25:51 process WindowServer[129] caught causing excessive wakeups. EXC_RESOURCE supressed due to audio playback

Jan 16 00:31:47 process WindowServer[129] thread 737885 caught burning CPU!; EXC_RESOURCE supressed due to audio playback

Jan 16 01:52:14 Over-release of kernel-internal importance assertions for pid 20 (syslogd), dropping 1 assertion(s) but task only has 0 remaining (0 external).

Jan 16 10:34:35 msdosfs_fat_uninit_vol: error 6 from msdosfs_fat_cache_flush

Jan 16 10:35:47 jnl: b(1, 2): replay_journal: from: 11310592 to: 17496064 (joffset 0xe8a000)

Jan 16 10:35:47 jnl: b(1, 2): journal replay done.

Jan 16 10:35:50 ** GPU Hardware VM is disabled (multispace: disabled, page table updates with DMA: disabled)

Jan 16 10:39:44 process WindowServer[148] caught causing excessive wakeups. EXC_RESOURCE supressed due to audio playback

Jan 16 15:16:14 Over-release of kernel-internal importance assertions for pid 36 (syslogd), dropping 1 assertion(s) but task only has 0 remaining (0 external).

Startup items

/Library/StartupItems/BRESINKx86Monitoring/BRESINKx86Monitoring

/Library/StartupItems/BRESINKx86Monitoring/BRESINKx86Monitoring.kext/Contents/I nfo.plist

/Library/StartupItems/BRESINKx86Monitoring/BRESINKx86Monitoring.kext/Contents/M acOS/BRESINKx86Monitoring

/Library/StartupItems/BRESINKx86Monitoring/StartupParameters.plist: Permission denied

Contents of /System/Library/LaunchAgents/com.apple.SafariPlugInUpdateNotifier.plist (XML document text)

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>EnablePressuredExit</key>

<true/>

<key>Label</key>

<string>com.apple.SafariPlugInUpdateNotifier</string>

<key>Program</key>

<string>/usr/libexec/SafariPlugInUpdateNotifier</string>

<key>LaunchEvents</key>

<dict>

<key>com.apple.fsevents.matching</key>

<dict>

<key>UserFlashPlugInModified</key>

<dict>

<key>Path</key>

<string>~/Library/Internet Plug-Ins/Flash Player.plugin</string>

</dict>

<key>SystemFlashPlugInModified</key>

<dict>

<key>Path</key>

<string>/Library/Internet Plug-Ins/Flash Player.plugin</string>

</dict>

</dict>

...and 3 more line(s)

Contents of /System/Library/LaunchDaemons/com.apple.installer.osmessagetracing.plist (XML document text)

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>Label</key>

<string>com.apple.installer.osmessagetracing</string>

<key>LaunchOnlyOnce</key>

<true/>

<key>ProgramArguments</key>

<array>

<string>/System/Library/PrivateFrameworks/OSInstaller.framework/Resources/OSMes sageTracer</string>

</array>

<key>UserName</key>

<string>root</string>

<key>GroupName</key>

<string>wheel</string>

<key>WatchPaths</key>

<array>

<string>/var/db/.AppleDiagnosticsSetupDone</string>

</array>

</dict>

</plist>

Contents of Library/LaunchAgents/com.apple.AddressBook.ScheduledSync.PHXCardDAVSource.UUID. plist (XML document text)

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>Label</key>

<string>com.apple.AddressBook.ScheduledSync.PHXCardDAVSource.UUID</string>

<key>ProgramArguments</key>

<array>

<string>/System/Library/Frameworks/AddressBook.framework/Resources/AddressBookS ourceSyncScheduleHelper</string>

<string>-scheduleSync</string>

<string>UUID</string>

</array>

<key>StartInterval</key>

<integer>120000</integer>

</dict>

</plist>

Contents of Library/LaunchAgents/com.apple.FolderActions.enabled.plist (XML document text)

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>Label</key>

<string>com.apple.FolderActions.enabled</string>

<key>OnDemand</key>

<false/>

<key>Program</key>

<string>/System/Library/CoreServices/Folder Actions Dispatcher.app/Contents/MacOS/Folder Actions Dispatcher</string>

</dict>

</plist>

Firewall: On

User login items

gfxCardStatus

- /Users/USER/.Trash/gfxCardStatus.app

iTunesHelper

- /Applications/iTunes.app/Contents/MacOS/iTunesHelper.app

Restricted files: 34

Elapsed time (s): 181

Yes.i strongly agree with you. I have exactly same issues and i strongly believe that is not GPU issue.

The only thing i can see is that the cooling of the iMac' is terrible and when GPU is stressed i have seen temps more than 92c and maybe the measurement is not accurate...and can easily be 100c...Install a good software to monitor temps and you will be suprised at what temps they working...Electronics cannot stand such temps.

So if it is like that the soldering balls of the GPU can easily melt resulting to bad GPU chip contact.

I have 2 imac's models and i was running to temperature problems to both.And is not dust or anything else as some people suggested..Windows pc's can run without temp problems even if you can't see the heatsinks from the dust...imac's they have terrible design of heatsinks.That's it.

But i like Apple operating systems...

I can't understand why Apple does not fixing this...Since imac mid 2010 till imac 14.2 exactly the same problem and worst.

Maybe you don't have the same problem Heli A.

I am sure at 90 % that coloured square and crash occur when GPU is cold. In the morning or after a long pause for example. So I try a trick discussed somewhere here ; run a HD video (non-stop) to warm the GPU. So before beginning a day, I open VLC and play HD video in loop. It doesn't interfere with other use and the temperature climbs from 40 C to approximately 58 to 62 with other computer use.

It SEEMS to have a positive effect. No coloured square de ****** for a couple of weeks.

But it's not a cure, just a crutch. I prepare myself to an oven experience...

Alex

iMac 21,5 in mi-2011, AMD Radeon HD 6750M 512 MB, 2,5 GHz Intel Core i5, memory 10 GB,

* f...g square ;o)

Hi dear friend. I solved it as i told you. It was temperature problem.

i dont want to post the solution because its so much time consuming and need some skills....but i can say that is a temperature design problem for sure.

Even if you going to oven it will reappear again....Install a good program for temps ( i have istat menus) and watch gpu temp in a heavy load..lets say one iray render. You will see reaching 100c....i dont know any electronic device that can run smoothly and reliable under such temps...

Be well 🙂

Imac 14,2 2013 i7 32gb ram nvidia gpu.

Also i forgot to tell you ..Before i did this hardware fix i installed El Capitan and looks that the new OSX helped...It's far better than Yosemite...but i like the Yosemite name..