Mid-2011 iMac: Graphics issue... again.

[mikehalloran]

Uhhh... no... That's not why it's there. Remove it and the fans spin at full speed.

There's crapware that will let you control the fan manually if you remove the temp sensor. Downside is that, since you've disabled the automatic cooling system, you now have to monitor and adjust it manually.

There are some wiring hacks that short it out and keep the fan from turning on. Same downside.

No thanks.

The 2009-10 can repurpose an optical drive sensor but that doesn't work for the 2011-on.

 

[insydney]

Replace the battery (should have done that 3–6 years ago). If not replacing the HDD (which you should), get a BR2013 from Amazon ($8) but if installing an SSD, a common CR2013 is fine.

While you're in there, replace the HDD with an SSD (takes an additional 5 minutes). Besides being the usual culprit, these develop problems beginning at the 3 year mark.

An experienced tech can do this in 15 minutes but they like to charge $75 because you don't know how easy it is.

Put it back together with blue tape. Turn it on—if fixed, re-install the screws. If the problem is still there, bake the GPU to reflow the solder joints.

The SSD will improve performance so dramatically, you'll wonder why you didn't do this 5–7 years ago when it was a thing.

If cracked solder joints turn out to be the problem, the HDD was the cause. Period. Apple finally figured that out in 2013—the 2014 non-SSD iMacs came with slower, cooler HDDs.

None of the hundreds of 2009–2014 iMacs where I replaced the HDDs and batteries at the 3–5 year mark has developed a GPU problem. Not one.

Put it back together with blue tape. Turn it on—if fixed, re-install the screws. If the problem is still there, bake the GPU to reflow the solder joints.

Q.. what is "Blue tape" ?
[automerge]1588035152[/automerge]

Uhhh... no... That's not why it's there. Remove it and the fans spin at full speed.

There's crapware that will let you control the fan manually if you remove the temp sensor. Downside is that, since you've disabled the automatic cooling system, you now have to monitor and adjust it manually.

There are some wiring hacks that short it out and keep the fan from turning on. Same downside.

No thanks.

The 2009-10 can repurpose an optical drive sensor but that doesn't work for the 2011-on.

so is it OK to leave the HD in there but not connect the sata cable, just have the temp sensor plugged in ? or is the temp connected to the data cale. if its not running it's not generating heat.

 

[insydney]

read through again and now realise 'blue tape' must be to save attaching everything on and off again, saving masses of frustration, sorry i thought it must be some magical tape.. duh i am learning slowly

 

[mikehalloran]

so is it OK to leave the HD in there but not connect the sata cable, just have the temp sensor plugged in ? or is the temp connected to the data cale. if its not running it's not generating heat.

You can't do that from 2011 on. The sensor is built into the HDD and the pickup integral to the wiring harness. The OWC sensor is a wiring harness extension that gets around this.

There are only about 40–50,000 posts on MacRumors about how to do it right while avoiding having to spend the $40. Every so-called solution cripples the automatic cooling, one way or the other, except the OWC harness.

You lift one end of the screen to replace the battery; the other to look at and replace the drive(s). You don't know what's in there and how it's been hooked up.

Replace the battery. With the iMac on its back, remove the glass, pull the screws out of the screen, lift the top up an inch and slide up till the bottom comes out of the groove. Now lift the bottom of the screen to access and replace the battery. Put it back together w/ a few pieces of tape. See if you still have a problem with the video. If so, you're doing a tear down to get to the GPU.

I've left some steps out and you'll need a couple of Torx drivers. iFixIt has the sizes. It's possible to replace the battery without disconnecting any internal cables. It takes me about 10 minutes one-handed—if I had two working arms, I could replace the battery in a 2011 iMac in 5.

 

[insydney]

wow.. that's incredible thanks so much
i have watched masses off clips over the past few days and was under the impression the battery was on the reverse side of the logic board.
its not made any easier by the fact that every model and size seems to be assembled differently, it is however extremely satisfying to gradually make sense out of it all. one really irritating part is that here in australia everything is so unobtainable domestically and shipping is v expensive, especially from USA
oh well c'est la vie
thanks again

 

[mikehalloran]

i have watched masses off clips over the past few days and was under the impression the battery was on the reverse side of the logic board.

That's the late 2009–2010, the only two years for that nonsense. WTF was Apple thinking?

BTW, if you have to do a tear-down, here's a tip. Get some white-out and mark the polarity of each connector. It's too easy to reconnect them wrong and a white mark on one side only keeps you from making such mistakes. Been there, made that mistake.

 

[RipperMagoo]

I curious if the OP's imac is still up and running. I did the bake and it lasted about 1 year so I cannot complain. However after reading through this post I see that I should have swapped the HDD for and SSD. I did go with the OWC sensor when I put in a new HDD but I went the wrong direction and put in a 8TB (oops). I'm researching this topic again because I was thinking about re-baking my GPU but now I see I have more of a HDD heating issue.

And, I'm going to throw in a battery while I'm at it.

 

[mikehalloran]

I curious if the OP's imac is still up and running. I did the bake and it lasted about 1 year so I cannot complain. However after reading through this post I see that I should have swapped the HDD for and SSD. I did go with the OWC sensor when I put in a new HDD but I went the wrong direction and put in a 8TB (oops). I'm researching this topic again because I was thinking about re-baking my GPU but now I see I have more of a HDD heating issue.

And, I'm going to throw in a battery while I'm at it.

Exactly. BTW, if you need an 8TB SSD, it's available.

8TB SSD

Because the QVO SSDs have only a 3 year warranty, I like these if you don't need 8TB because of the 5 yr warranty. BTW, the SanDisk 3D Ultra is the exact same Toshiba drive from the same company — WD now owns SanDisk.

WD Blue 3D 1–4TB

There are a number of adapters of this design made of aluminum or pot metal. I've not noticed that makes any difference and have used both. Besides being a convenient way to mount, it increases airflow inside the iMac which is better for both the drive and GPU.

2.5" adapter

I sold my 2011 a few weeks ago with an SSD, open bracket, OWC temp sensor and new battery (of course) to someone looking to run old apps over El Capitán. She got a great bargain for the $500 I charged her and that machine should run for many years.

 

[mdgm]

SSDs run cooler and faster with the main drawback being the higher price per TB. They are continuing to become more affordable over time.

 

[RipperMagoo]

Exactly. BTW, if you need an 8TB SSD, it's available.

8TB SSD

Because the QVO SSDs have only a 3 year warranty, I like these if you don't need 8TB because of the 5 yr warranty. BTW, the SanDisk 3D Ultra is the exact same Toshiba drive from the same company — WD now owns SanDisk.

WD Blue 3D 1–4TB

There are a number of adapters of this design made of aluminum or pot metal. I've not noticed that makes any difference and have used both. Besides being a convenient way to mount, it increases airflow inside the iMac which is better for both the drive and GPU.

2.5" adapter

I sold my 2011 a few weeks ago with an SSD, open bracket, OWC temp sensor and new battery (of course) to someone looking to run old apps over El Capitán. She got a great bargain for the $500 I charged her and that machine should run for many years.

Thanks Mike, I appreciate all the information. I got a handful of 8TB drives from a friend and figured while I had it open to bake the video card I'd throw one in. Before the video card failed again I had about 3.5 TB of video and photos on it. When I do decide to take this on I won't be looking for an SSD that large.
I see 8TB HDD was a mistake on many levels.

Thanks again,
Chris

 

[mikehalloran]

Thanks Mike, I appreciate all the information. I got a handful of 8TB drives from a friend and figured while I had it open to bake the video card I'd throw one in. Before the video card failed again I had about 3.5 TB of video and photos on it. When I do decide to take this on I won't be looking for an SSD that large.
I see 8TB HDD was a mistake on many levels.

Thanks again,
Chris

Besides running a lot cooler, an SSD will be so much faster, you’ll think you have a new iMac.

 

[Nguyen Duc Hieu]

If you need a 100TB SSD in 3.5" form factor, it's available, too. Provided that you are willing to spend a lot of money.

 

[mikehalloran]

If you need a 100TB SSD in 3.5" form factor, it's available, too. Provided that you are willing to spend a lot of money.

I like your sense of humor. Can anyone imagine spending, $40,000 for one of these to put inside a 2011 iMac? Not even the more money than brains crowd would do that.

For $40,000 one could buy a 28 core Mac Pro 7.1 and load it up with 100TB NVMe storage*, a Vega Pro II Duo, Afterburner and the $6k monitor.

8TB onboard plus 7 of these on PCIe cards:

https://eshop.macsales.com/item/OWC/S4DAQ12ST80/

 

[wazgilbert]

Guess what I had to do today?

200C for 8 minutes and we were back running again.

last had to do this 18 months ago.
The machine itself was a gift when it failed the first time and the guy put a few different ram sticks and hard drives in it before giving it to the local ‘you like macs don’t you?’ Guy

It’s a 2011 27” i7 with the 1Gb 6970

 

[Nguyen Duc Hieu]

I wasn't lucky like you in baking half dead GPUs.
My iMacs late 2009 got a half-dead HD4850 (could boot to desktop, but running anything that graphic acceleration like watching youtube will result in a total halt.
I took the card out and brought it to a laptop repair shop to have it baked on professional machine (the heat would focus on the GPU chip only). It was the same as before, not better, not worse. So I guess in my case the GPU chip was bad.
But luckily I have a Quadro K1100m. Now my iMac 2009 is alive again, ready to be installed with Big Sur....

 

[Basewrecker]

If you have an HDD in it, the cause of the problem is still there. Baking works by reflowing the solder. Over heating and cooling caused the joints to crack. The heat source is the hard drive inside.

Replacing it with an SSD eliminates the heat source and lets the iMac run a lot faster.

Hey! So I put a ssd in my 2011 iMac so is there a chance for a gpu failure? I didn't reattach the sensor tho, I use a fan controller app to control the fans.

 

[mdgm]

Hey! So I put a ssd in my 2011 iMac so is there a chance for a gpu failure? I didn't reattach the sensor tho, I use a fan controller app to control the fans.

An SSD gives off less heat than a HDD so it should be better for the GPU. Provided you set reasonable fan control settings it should reduce the chance of GPU failure, but YMMV.

 

[mikehalloran]

Hey! So I put a ssd in my 2011 iMac so is there a chance for a gpu failure? I didn't reattach the sensor tho, I use a fan controller app to control the fans.

It's 10 years old and anything can happen if it was already on the verge of failure, I suppose, but you've lessened the chance. Not one of the hundreds that I upgraded with SSDs 4–6 years ago have failed.

Hopefully, you replaced the NV RAM battery at the same time. If not, takes 5 minutes for someone who's done it a lot; 10 minutes for everyone else. When the battery voltage is too low, the symptoms mimic GPU failure. With an SSD in there, a common CR2032 battery is fine — you do not need the high-heat BR2032 for obvious reasons.

You can't "reattach the temp sensor" on a 2009 and later so I guess it's good you didn't. Although there are inexpensive workarounds for the 2009–10 27", the 2011–15 is different.
OWC 2011-on iMac Temp Sensor

I do not like the fan controller apps. Ok, you saved the $38 by not buying the OWC Temp Sensor, so now you have to monitor the temperature and control the fans manually? No thanks. Installing the sensor is not as fast as replacing the battery but once you've been in there, it's fast enough — takes me 15 minutes to install the sensor and battery on a 2011 27" and I do it one-handed because of my handicap.

 

[Basewrecker]

It's 10 years old and anything can happen if it was already on the verge of failure, I suppose, but you've lessened the chance. Not one of the hundreds that I upgraded with SSDs 4–6 years ago have failed.

Hopefully, you replaced the NV RAM battery at the same time. If not, takes 5 minutes for someone who's done it a lot; 10 minutes for everyone else. When the battery voltage is too low, the symptoms mimic GPU failure. With an SSD in there, a common CR2032 battery is fine — you do not need the high-heat BR2032 for obvious reasons.

You can't "reattach the temp sensor" on a 2009 and later so I guess it's good you didn't. Although there are inexpensive workarounds for the 2009–10 27", the 2011–15 is different.
OWC 2011-on iMac Temp Sensor

I do not like the fan controller apps. Ok, you saved the $38 by not buying the OWC Temp Sensor, so now you have to monitor the temperature and control the fans manually? No thanks. Installing the sensor is not as fast as replacing the battery but once you've been in there, it's fast enough — takes me 15 minutes to install the sensor and battery on a 2011 27" and I do it one-handed because of my handicap.

I didn't replace the NV RAM battery, but if and when the gpu dies I'll bake the gfx card and replace the battery while it. Also 3 weeks ago the Mac rebooted itself two times, not a kernel panic as it didn't say "your Mac ran into a problem" but when I booted into the os I was greeted with a crash report *I forgot what it said but it was related to the gpu* but is this a sign of the NV RAM battery dying?

 

[mikehalloran]

I didn't replace the NV RAM battery, but if and when the gpu dies I'll bake the gfx card and replace the battery while it. Also 3 weeks ago the Mac rebooted itself two times, not a kernel panic as it didn't say "your Mac ran into a problem" but when I booted into the os I was greeted with a crash report *I forgot what it said but it was related to the gpu* but is this a sign of the NV RAM battery dying?

I didn't say it was the only symptom. Loss of settings is the one people look for which is why only techs seem to know about the GPU. Yes, you need to do this.

The battery is available at any drug or grocery store. To replace is really easy. Pull the glass and screen screws as before. Lay it on its back. Lift the top of the screen and pull towards you about 3/4" till you can see the bottom has cleared its channel. Now lift the bottom of the screen and you'll see the battery (you may have to pull the screen back a little to raise it up). Poke a toothpick in the hole or slot in the side of the bracket and the battery will pop up. You'll see how to put the new one in. Replace the screws and glass.

Nothing to disconnect except the power cord.

 

[Basewrecker]

Oo I never knew about the loss settings but Ill keep it in mind! I'll replace the battery this weekend, thanks for the help!

 

[mikehalloran]

Oo I never knew about the loss settings but Ill keep it in mind! I'll replace the battery this weekend, thanks for the help!

Oh yea, that's why it's there. Back in the day (I go way back), Mac lost its settings? Replace the battery. Anything past 5 years was really pushing it.

The first time I encountered a battery/GPU issue was on a B&W G3. I got called to one of my schools to diagnose a black screen — had never seen that as monitors and GPUs generally showed warning symptoms long before. Cable was good (nice about a classroom was that I could A/B monitors and cables). So, seeing that it was 5 years old and still had its PRAM (PPCs have PRAM; Intel is NV RAM — same function) battery, I replaced it because I always carried spares. The monitor came back to life. Huh?

Who knew? Turns out that my Apple engineering friends did.

Except for the 2009–10 27", all iMacs have it on the front. The 2009-10 have it on the back of the motherboard — WTF was Apple thinking?

 

[CooperBox]

I realise this is a fairly old thread but as I'm just about to completely refurbish a 27" mid-2011 iMac I thought it still relevant. I've succesfully performed this on 2009 and 2010 27" iMacs.
@mikehalloran
You appear very knowledgeable and I've enjoyed reading your posts. I certainly agree with most of what you say. However I have several queries hopefully you can answer:

i) In post #26 you say, "There's crapware that will let you control the fan manually if you remove the temp sensor. Downside is that, since you've disabled the automatic cooling system, you now have to monitor and adjust it manually."
If you are referring to MacFanControl (or similar), my take is that the software provides a very competent solution in certain circumstances. It's no secret that Apple have long been an advocate for quiet system operation, often achieved by default relatively slow running fans, at the expense of inadequate cooling - leading to excessive heat and potential component failure.

ii) In post #24 you advocate the use of the OWC in-line digital thermal sensor upgrade cable for the 27" 2011.
Do you still have the same take on this? I'm asking as it appears that there are multiple posts by users and also knowledgeable techs that the OWC temp sensor is a scam. From experience I recall that either on the 27" 2009 or 2010 models (I can't recall which) removing the Apple HDD and installing an SSD will result in fans running at full speed. I was aware of this beforehand so simply isolated wires on the sata HDD connector. From research over the past few days I've understood that replacing the HDD by an SSD will have no adverse effect on fan operations on a 2011 27" iMac. If I'm mistaken on that I'll simply isolate two of the HDD connector wires.
So my basic question is on the true need/effectiveness of an OWC temp sensor? I appreciate that if you are an Apple or an OWC employee you may skip the answer.

iii) In post #19 & #22 you say, " I've replaced the HDDs on hundreds of late 2009–2013 iMacs within 5 years in schools. Over 100 were the 2011-12 with the supposed GPU problem. Total number of GPU failures=0".
"None of the hundreds of 2009–2014 iMacs where I replaced the HDDs and batteries at the 3–5 year mark has developed a GPU problem. Not one."
I have no need to doubt this and admire your dedication/professionalism. Simple question, what is the longest running period any of those iMac reflow GPU's have obtained to date?
My personal 'record' link HERE, is just over one year on a 2009 27" iMac.

 

[mikehalloran]

I'll be brief.

The problem with the fan control crapware is that, once installed, it overrides the Mac's sensors. It doesn't allow you to control speed; it requires you to do this. Big difference. If there's a utility that allows you to toggle this functionality on/off, that might be useful —I don't know of any.

Who's doing extensive AV or playing intensive games on a nearly 11 year old Mac that they need manual control? No one except for those not willing to purchase the right fan controller for this machine.

The OWC Temp Sensor is the only reliable solution for the 2011–14 that I've found. It's not the same one that they sell for the 2009–2010. The late '09–'10 can use an inexpensive optical sensor taped to the SSD but not the 2011. OWC does recommend it for the '15–'17 iMacs but I don't know why unless it's the Education models that may have had 3.5" HDDs—the schools I worked for did not buy those. The 'everything is a scam' boys can safely be ignored.

There is a blade type SSD for the unused SATA plug in a 2011. It's expensive, hard to find, low capacity and doesn't need a fan control. You can even find adapters that allow you to plug a 2.5" drive into that plug but I don't recommend it. The OWC Temp sensor costs less and keeps the fans running properly.

My normal recommendations still stand:

Remove the HDDs from every Intel Mac. Now that 2.5" SSDs are available up to 8TB, the Mickey Mouse solutions often advocated around here border on the ridiculous.

Do not disable the automated cooling system.

Replace the NV RAM battery (a CR2032 is fine) every 5 years.

Your machine will run cooler and the GPU gremlins will leave you alone.

A 2011 can still run High Sierra and are still viable. Mine is running like a top with a 2TB Crucial MB500 and the OWC sensor properly installed.

 

[CooperBox]

I thank you for your reply. So I understand you are saying that on a 2011 27" iMac if I remove the current HDD, do not fit another but install an SSD, the fans will default to run at high speed without futher intervention. If so, obviously not a situation I want, and in that case have no problem whatsoever with purchasing the specific 2011 OWC Temp Sensor. I wasn't aware that their 2009/10 and 2011 sensors were different, that is indeed worth knowing.