Q: Red and green square dots?

Here's a temporary fix that appears to work. I noticed that the dots show up big time when my imac goes into extended sleep mode. I would log in start working and within 2- 3 minutes everything would lock up forcing me to do a hard reboot and then everything would be fine or workable until the next time.

Suspecting it had something to do with automatic sleep mode - I now shut down running programs and then manually put the machine into sleep mode before I retire for the night. In the morning I usually have no issues as long as I stick to the routine and don't let it stay unused for any extended period of time which I am guessing is more than 2 or 3 hours.

Hope this helps as an alternative to baking.

The reason this happens is cooling. As the GPU cools very small gaps form in the solder.  When it heats up it the solder expands and makes the gaps smaller.  Baking reflows this and should re-fill the gaps.  This will get progressively worse.

Hello all.  I didn't scroll through all the pages of this thread, so perhaps the following detail has already been mentioned:

I mostly run using Win7 bootcamp on my Mid 2010 27" Mac.  Recently, I switched to Yosemite 10.10.2 as the primary OS over Win7, and the screen problems appeared in force.  When I go back to Win7, even for for a week or more, the problem goes away entirely.  I don't have a single display issue while running Win7, and now I get constant display issues when running 10.10.2.   There must be something in the way Windows uses the graphics card power management (either very efficiently, or very inefficiently) that keeps the problem from surfacing.

It's too bad, because I prefer the Mac interface, but it sound like short of baking the Graphics card, I may have to revert back to Win7 if things get worse.

Just a quick note to report that it's now been two weeks since I baked my GPU (200C, 7 minutes), and my iMac has been working fine since then.

Just one episode of screen-freezing-except-pointer, which of course I'm not sure if could be related to the cold solder issue.

Just another member of the iMac 27-inch, Mid 2010 2.93 GHz Intel Core i7 ATI Radeon HD 5750 1024 MB red an green square dot freeze club, two years running. On occasion my iMac will generate this report after a freeze and restart which i send in to apple with a link to this topic as the steps necessary to recreate problem:

Anonymous UUID:       8954FBFD-6C0E-F0E3-EF9B-2BC43B710678

Wed May  6 17:39:13 2015

panic(cpu 1 caller 0xffffff800b2dcc1d): Kernel trap at 0xffffff800b2c84fc, type 13=general protection, registers:

CR0: 0x0000000080010033, CR2: 0x0000000118ace000, CR3: 0x0000000116e82000, CR4: 0x0000000000000660

RAX: 0x4394df4d00000000, RBX: 0x0000000000000000, RCX: 0xffffff800b8d1770, RDX: 0xffffff8033e50998

RSP: 0xffffff811626bc60, RBP: 0xffffff811626bcc0, RSI: 0xffffff8033e50997, RDI: 0xffffff8018f7f600

R8:  0x0000000000018cb0, R9:  0x0008000000018cb0, R10: 0xffffff800b8d2a78, R11: 0x0000000000000200

R12: 0x000000000000012c, R13: 0xffffff8033e50998, R14: 0x0000000000018cb0, R15: 0x00000001abd2b000

RFL: 0x0000000000010207, RIP: 0xffffff800b2c84fc, CS:  0x0000000000000008, SS:  0x0000000000000010

Fault CR2: 0x0000000118ace000, Error code: 0x0000000000000000, Fault CPU: 0x1

Backtrace (CPU 1), Frame : Return Address

0xffffff810e09ddf0 : 0xffffff800b223139

0xffffff810e09de70 : 0xffffff800b2dcc1d

0xffffff810e09e040 : 0xffffff800b2f4486

0xffffff810e09e060 : 0xffffff800b2c84fc

0xffffff811626bcc0 : 0xffffff800b2c6104

0xffffff811626bda0 : 0xffffff800b2c6657

0xffffff811626be00 : 0xffffff800b27e77a

0xffffff811626bf10 : 0xffffff800b282a4f

0xffffff811626bf40 : 0xffffff800b21d307

0xffffff811626bf70 : 0xffffff800b2ca13d

0xffffff811626bfb0 : 0xffffff800b2f4ca6

BSD process name corresponding to current thread: iMovie

Mac OS version:

13F1077

Kernel version:

Darwin Kernel Version 13.4.0: Wed Mar 18 16:20:14 PDT 2015; root:xnu-2422.115.14~1/RELEASE_X86_64

Kernel UUID: 8B1A8FD1-2344-36C0-A7F5-D9D485A995FA

Kernel slide:     0x000000000b000000

Kernel text base: 0xffffff800b200000

System model name: iMac11,3 (Mac-F2238BAE)

System uptime in nanoseconds: 73153811693281

last loaded kext at 3407276216447: com.apple.driver.AppleUSBCDC 4.2.1b5 (addr 0xffffff7f8d8a6000, size 20480)

last unloaded kext at 3474211365435: com.apple.driver.AppleUSBCDC 4.2.1b5 (addr 0xffffff7f8d8a6000, size 16384)

loaded kexts:

com.apple.driver.AudioAUUC 1.60

com.apple.driver.AppleBluetoothMultitouch 80.14

com.apple.driver.AppleHWSensor 1.9.5d0

com.apple.driver.AGPM 100.14.34

com.apple.filesystems.autofs 3.0

com.apple.iokit.IOBluetoothSerialManager 4.2.7f4

com.apple.driver.AppleMikeyHIDDriver 124

com.apple.driver.AppleMikeyDriver 2.6.3f4

com.apple.driver.AppleUpstreamUserClient 3.5.13

com.apple.kext.AMDFramebuffer 1.2.4

com.apple.driver.AppleHDA 2.6.3f4

com.apple.AMDRadeonX3000 1.2.4

com.apple.iokit.IOUserEthernet 1.0.0d1

com.apple.Dont_Steal_Mac_OS_X 7.0.0

com.apple.driver.AppleBacklight 170.4.11

com.apple.kext.AMD5000Controller 1.2.4

com.apple.driver.AppleHWAccess 1

com.apple.driver.AppleMCCSControl 1.2.5

com.apple.driver.AppleLPC 1.7.0

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 4.2.7f4

com.apple.driver.ACPI_SMC_PlatformPlugin 1.0.0

com.apple.driver.AppleIRController 325.7

com.apple.driver.AppleUSBCardReader 3.4.1

com.apple.driver.Oxford_Semi 3.4.1

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeLZVN 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0d1

com.apple.BootCache 35

com.apple.iokit.SCSITaskUserClient 3.6.7

com.apple.driver.XsanFilter 404

com.apple.iokit.IOAHCIBlockStorage 2.6.0

com.apple.driver.AppleUSBHub 683.4.0

com.apple.driver.AppleFWOHCI 5.0.2

com.apple.driver.AirPort.Atheros40 700.74.5

com.apple.iokit.AppleBCM5701Ethernet 3.8.1b2

com.apple.driver.AppleAHCIPort 3.0.5

com.apple.driver.AppleUSBEHCI 660.4.0

com.apple.driver.AppleACPIButtons 2.0

com.apple.driver.AppleRTC 2.0

com.apple.driver.AppleHPET 1.8

com.apple.driver.AppleSMBIOS 2.1

com.apple.driver.AppleACPIEC 2.0

com.apple.driver.AppleAPIC 1.7

com.apple.driver.AppleIntelCPUPowerManagementClient 217.92.1

com.apple.nke.applicationfirewall 153

com.apple.security.quarantine 3

com.apple.driver.AppleIntelCPUPowerManagement 217.92.1

com.apple.driver.AppleBluetoothHIDKeyboard 170.15

com.apple.driver.AppleHIDKeyboard 170.15

com.apple.driver.IOBluetoothHIDDriver 4.2.7f4

com.apple.driver.AppleMultitouchDriver 245.13.1

com.apple.kext.triggers 1.0

com.apple.iokit.IOSerialFamily 10.0.7

com.apple.driver.DspFuncLib 2.6.3f4

com.apple.vecLib.kext 1.0.0

com.apple.iokit.IOAudioFamily 1.9.7fc2

com.apple.kext.OSvKernDSPLib 1.14

com.apple.iokit.IOAcceleratorFamily 98.26

com.apple.iokit.IOSurface 91.2

com.apple.iokit.IOBluetoothFamily 4.2.7f4

com.apple.driver.AppleBacklightExpert 1.0.4

com.apple.iokit.IONDRVSupport 2.4.1

com.apple.iokit.IOFireWireIP 2.2.6

com.apple.kext.AMDSupport 1.2.4

com.apple.AppleGraphicsDeviceControl 3.6.22

com.apple.driver.AppleSMBusController 1.0.12d1

com.apple.driver.AppleSMBusPCI 1.0.12d1

com.apple.driver.AppleHDAController 2.6.3f4

com.apple.iokit.IOGraphicsFamily 2.4.1

com.apple.iokit.IOHDAFamily 2.6.3f4

com.apple.iokit.IOBluetoothHostControllerUSBTransport 4.2.7f4

com.apple.driver.AppleSMC 3.1.8

com.apple.driver.IOPlatformPluginLegacy 1.0.0

com.apple.driver.IOPlatformPluginFamily 5.7.1d6

com.apple.iokit.IOUSBHIDDriver 660.4.0

com.apple.iokit.IOSCSIBlockCommandsDevice 3.6.7

com.apple.iokit.IOUSBMassStorageClass 3.6.0

com.apple.iokit.IOFireWireSerialBusProtocolTransport 2.5.1

com.apple.iokit.IOFireWireSBP2 4.2.6

com.apple.driver.AppleUSBMergeNub 650.4.0

com.apple.driver.AppleUSBComposite 656.4.1

com.apple.iokit.IOSCSIMultimediaCommandsDevice 3.6.7

com.apple.iokit.IOBDStorageFamily 1.7

com.apple.iokit.IODVDStorageFamily 1.7.1

com.apple.iokit.IOCDStorageFamily 1.7.1

com.apple.iokit.IOAHCISerialATAPI 2.6.1

com.apple.iokit.IOSCSIArchitectureModelFamily 3.6.7

com.apple.iokit.IOFireWireFamily 4.5.5

com.apple.iokit.IOUSBUserClient 660.4.2

com.apple.iokit.IO80211Family 640.36

com.apple.iokit.IOEthernetAVBController 1.0.3b4

com.apple.driver.mDNSOffloadUserClient 1.0.1b5

com.apple.iokit.IONetworkingFamily 3.2

com.apple.iokit.IOAHCIFamily 2.6.5

com.apple.iokit.IOUSBFamily 686.4.1

com.apple.driver.AppleEFINVRAM 2.0

com.apple.driver.AppleEFIRuntime 2.0

com.apple.iokit.IOHIDFamily 2.0.0

com.apple.iokit.IOSMBusFamily 1.1

com.apple.security.sandbox 278.11.2

com.apple.kext.AppleMatch 1.0.0d1

com.apple.security.TMSafetyNet 7

com.apple.driver.AppleKeyStore 2

com.apple.driver.DiskImages 371.1

com.apple.iokit.IOStorageFamily 1.9

com.apple.iokit.IOReportFamily 23

com.apple.driver.AppleFDEKeyStore 28.30

com.apple.driver.AppleACPIPlatform 2.0

com.apple.iokit.IOPCIFamily 2.9

com.apple.iokit.IOACPIFamily 1.4

com.apple.kec.corecrypto 1.0

com.apple.kec.pthread 1

Model: iMac11,3, BootROM IM112.0057.B01, 4 processors, Intel Core i7, 2.93 GHz, 8 GB, SMC 1.59f2

Graphics: ATI Radeon HD 5750, ATI Radeon HD 5750, PCIe, 1024 MB

Memory Module: BANK 0/DIMM0, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

Memory Module: BANK 1/DIMM0, 2 GB, DDR3, 1333 MHz, 0x80CE, 0x4D34373142353637334648302D4348392020

Memory Module: BANK 0/DIMM1, 2 GB, DDR3, 1333 MHz, 0x859B, 0x435432353636344243313333392E4D313646

Memory Module: BANK 1/DIMM1, 2 GB, DDR3, 1333 MHz, 0x859B, 0x435432353636344243313333392E4D313646

AirPort: spairport_wireless_card_type_airport_extreme (0x168C, 0x8F), Atheros 9280: 4.0.74.0-P2P

Bluetooth: Version 4.2.7f4 15112, 3 services, 23 devices, 1 incoming serial ports

Network Service: AirPort, AirPort, en1

Serial ATA Device: WDC WD1001FALS-40Y6A0, 1 TB

Serial ATA Device: OPTIARC DVD RW AD-5680H

USB Device: Hub

USB Device: Ext HDD 1021

USB Device: Internal Memory Card Reader

USB Device: BRCM2046 Hub

USB Device: Bluetooth USB Host Controller

USB Device: Hub

USB Device: Back-UPS ES 750 FW:841.I3 .D USB FW:I3

USB Device: Built-in iSight

USB Device: IR Receiver

FireWire Device: G-DRIVE, HGST, Up to 800 Mb/sec

Thunderbolt Bus:

May 15, 2015 - I spent the day upgrading to Mavericks.

Finished early this evening.

Green and Pink "dots" are appearing. To be precise, they are like very enlarged square pixels.

Have NEVER had this issue before upgrading today. NEVER. I do not believe it is a hardware issue as I have owned this mac since 2010 with ZERO issues. Had HD replaced per the recall. That is all. Have used machine heavily for photo editing, video editing, and heavy graphic design with ZERO issues. Until today.

Software update  - MAVERICKS - broke my monitor/imac. Not happy at all.

Its been a month since my last post - and my temporary solution is working fine - keep your machine on  and manually put it to sleep if you are going to keep it unattended for more than say 2 hours. If I break the rule the dots come back to the point of freezing the computer and forcing a hard reboot. Luckily that sets it back on track. Not as extreme as baking the cpu and my experience definitely does not suggest its a hardware issue. Hope that helps.

After months of relative inactivity on this front, these past two or three days my dancing "pixels" (red and green, shimmering) have occasionally returned - culminating in a literal explosion of violent color blasts: Today, all my open windows began scrolling red and green patterns - wave after wave of incessant bombardment... to the point where I had to force a manual shutdown and restart.

For the past couple of days, I'd find my iMac 27 (mid-2010, i5, 2.8) in a frozen state each morning, which has also required that manual shutdown/re

I've been running many, many months now with no energy saver settings: monitor and hard drive set to "never sleep"..

I'm thinking that my video card is about to explode?

Seeing recent announcements regarding the expansion/extension of repair programs for other model experiencing similar issues, I'm feeling slighted that our 2010 iMac were never considered important enough to merit similar consideration.

This from a confirmed "Mac-man" since 1984, whose present household includes a 27" iMac, a 24" iMac, a 21" iMac, a MacBook Air 13", a MacBook Pro 15" Retina, 4 Apple TV's, 3 iPad 4's, a plethora of iPods, 4 iPhone 5S's, two Airport Extremes (6-antenna) .. and an array of various and sundry peripherals.

Apple - are you even LISTENING????

it has been 4 days since my upgrade to mavericks and after my initial rant, I am pleased to say the dots have subsided. I now live in fear that they will suddenly reappear when I am neck deep in a project and I won't be so lucky as I was this time. also I am pleased to find out that I have an almost 5 year old machine that does everything I need it to, still. fingers crossed folks.

Just as feared - not even 24 hours later and they are back. frustrating

Just sold my 2010 27" iMac and bought the 27" 5K on Saturday. This morning, I started getting occasional red dots, jaggies and some squares with what looks like little clips of pictures (if that makes sense). Tried rebooting, but I still saw them even as it booted up. They went away and all was good until about 20 minutes ago when I started getting a few here and there. They also went away after a few minutes, but just not sure what is going on. I don't see the full screen coverage like many have posted, but occasional ones here and there.

My 2010 never had this issue. My computer is not running hot at all (actually quite cool).

Not sure whether to bring it back to Best Buy, Wait and see, or just call Apple.

I did notice yesterday that Safari would freeze when I was running "speedofme" bandwidth test. Chrome did not freeze for this.

Thoughts?

Hi all,

I'm suffering exactly the same issues, running a 21.5-inch, medio 2011 iMAC, with... a AMD Radeon HD 6770M 512 MB ! The problem started about 1 year ago (August 2014), I believe after an update to OS X 10.9.4.

The scenario is alike as described in this post

- colored squares appear on the screen,

- with some bad luck it's like ' a waterfall', and the screen is full of them,

- if you're lucky: they disappear

- there is a much higher probability that they appear in iPhoto (which I use very frequently...)

- in 70 % of the cases, the system crashes completely: hanging ...

- no entry in logs is made

--> frustration guaranteed !!!

I brought my iMAC to an Apple repair-centre here in Belgium; they tested the machine for 1 week and could not find anything :-( also extensive HW-test didn't show anything.

Any help is welcomed...

Peter

Since I posted about my issues, I have not had it again. I used clean my mac to find any traces of Logitech drivers on my computer and deleted them. Someone had suggested this. Fingers crossed, but it has been a very long time without issue

I've been watching this board, and keeping track of the various fixes offered. If your warranty is still in effect, than Applecare is a very good option. But many owners of 2010 iMac won't have their warranty in force anymore. Repair can be extremely expensive.

Aside from getting the logic/graphics board replaced, there's one solution I'm surprised no one mentioned: reballing.

http://www.us-tech.com/RelId/856201/pagenum/2/ISvars/default/A_User

With BGA reballing, someone removes all of the solder on your board, and uses fresh solder and thermal paste to make sure the connection doesn't degrade. The advantages include (1) BGA reballing costs considerably less than a logic/graphics board, and (2) it's more reliable longterm than either a logic board replacement or solder reflow; in fact, reflow usually lasts only a few months before it starts to fail.

I can happily report that since toaster over reflowing my card in October, I have not had any issues at all, and that includes going through the coldest winter in history...the previous two winters would really cause graphics issues on the coldest days. I had been going through it for YEARS, the last 8 months have been a pleasure!