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iMac (27-inch, Mid 2011) AMD Radeon HD 6970M 1GB card revived... by baking!

Sebastian -

iMac Intel 27" EMC 2429

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Installing iMac Intel 27" EMC 2429 Dual Drive Kit (HDD or SSD)

1 hour

Moderate

My Problem

My iMac first started showing symptoms by rebooting intermittently. A few days later, the infamous thick bars would appear on the display, at which point the iMac would reboot. The computer would boot back to the desktop and would be usable for a very short period of time before repeating the cycle.

A replacement graphics card for this model (directly from Apple) will run you about $400, plus labor. For that price, you’re better off getting a re-balled 2GB version of the card on eBay for about $300. I work as a repair tech, so I’m used to digging through the innards of Apple machines. I had heard/read of people bringing their graphics cards back to life by simply baking them before I began this whole repair. Considering the price for a replacement/repair, I figured what the !&&*, in the oven you go!

My Fix

I preheated the oven and baked the graphics card for about 10-12 minutes @ ~380-390°F (about 200°C). I then let the card cool down for about 30 minutes. In the meantime, I thoroughly cleaned the graphics card heat sink using alcohol pads and also took the time to clean out the rest of iMac. Once the card cooled down, I cleaned the GPU chip and memory modules again (they were cleaned before the card went in the oven) and reapplied the thermal paste/pads. I used Arctic Silver 5- people might say it’s overrated, but it’s always given me the lowest temps on all of my builds. Once all the new thermal material was applied, I reinstalled the graphics card heatsink & reassembled the rest of the machine.

I plugged the iMac in and powered it on. As soon as I heard the chime and the display turned on (joy!), I reset the PRAM/NVRAM. The iMac power-cycled and then booted successfully to the desktop. So far so good. I let the computer run for a minute or two, rebooted, and ran diagnostics- every component passed except for the HDD temperature sensor. I was already aware of this, as I had upgraded to a 3TB HDD which did not include the port for the temp. cable (this is the case with the majority of non-Apple branded HDDs). This issue can be solved by using fan control/monitoring software, such as HDD/SSD Fan Control. Otherwise, I highly recommend OWC’s In-line Digital Thermal Sensor, which easily attaches to the HDDs current power cable. You can then peel the adhesive on the included thermal sensor and place it directly on the HDD. Regardless of whether you choose the software or hardware fix, they both remedy the sensor issue- or rather, the fan issue (HDD fan spinning at over 4000rpm).

My Advice

Post-repair, my average GPU Die temperature is posting at about 45°C during normal use. I ran Unigine Valley Benchmark using all of the “basic” presets, with the exception of selecting 1920×1080 instead of 1280×720 as the resolution. I ran the GPU stress test under these conditions for about 15 minutes. The GPU Die temp slowly began to rise, peaking at around 90°C (I later ran an extended test for about 8 hours and the log indicates that the temperature never exceeded 93°C). Comparing those numbers to my pre-repair temperatures: ~60°C during normal use, 100-105°C during heavy use, I’d say the new thermal compound is working its magic! Although 90°C is on the higher side when it comes to graphics card temperatures, these cards can safely operate up to 100°C under heavy load. I should also mention that the iMac did not crash at any point during the GPU stress testing.

Judging by the overall temps of the machine, I can definitely see that the repair helped. I’m pretty happy with these temperatures- running the GPU stress test is probably the most… stress… the iMac will experience. The computer is primarily used for day-to-day tasks (email, web, etc.) as well as photo editing using Adobe Photoshop & Lightroom, with some occasional video editing/encoding. I don’t expect to see the GPU temp go above 80°C. If I ever feel uneasy about the GPU temp, I can always get the fans to kick in using iStat Menus (or any other fan control software).

The iMac has been powered on for exactly 1 week now with no issues! I just installed a Samsung 850 Pro SSD underneath the ODD, while keeping the 3TB HDD in the main bay for storage. Speed-wise, the iMac is giving some of the new models a good run for their money!

iMac Intel 27" (Mid 2011) Dual Hard Drive Kit Image
iMac Intel 27" (Mid 2011) Dual Hard Drive Kit

$27.99

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43 Comments

Hi Nice job! I am planning of baking my gpu this weekend but I dont have those "thermal pads" do you know if they are required? or can I just use artic silver on the memory chips?

Markus - Reply

Sorry for the delay- just saw your comment. I think the thermal pads are the way to go- if you try using paste on the memory chips, there *most likely* will be a gap between the heatsink and the surface of the chips. You should be able to find thermal pads in bulk on eBay, or elsewhere online. Be sure to get ones that are as thick as the ones currently being used.

Sebastian - Reply

Hey great job! I had just ordered a used gpu off eBay but now I'm going to try baking my old one. It got to the point where the computer would even boot all the way. About the SSD upgrade. Since you have installed the SSD have you noticed your gpu temps higher on average? I'm just wondering about this since the SSD is going under the cd drive. It seems like it would block the path of airflow from the fan below to the heartsink for the gpu? Thanks!

Shute - Reply

I was just about to order the new card today when I saw this. I figured, why not try it? Worked like a charm!! Great write up!! Thanks Sebastian!!

Darrell - Reply

Just wanted to add this:

I had fan issues and tried resetting the SMC and PRAM several times. I took the thing apart half a dozen times to make sure I had everything plugged in correctly. I measured each sensor (disconnected) and got roughly 5.2 MOhms on each one. This eliminated bad cables or sensors like all the other forums say.

Basically, the connectors are not the best. I disassembled the iMac completely again, and removed the logic board. I reinstalled it and slowly connected everything back up. On the sensor wires, I used the spudger to push the pins further into the connector, after they were connected. Buttoned it all up and without needing to reset anything, all of the fans were running nice and quiet. Everything is looking good. Hopefully the baking experiment will keep the video card going for a while.

Darrell -

Hi, Sebastian. I read your fix with a lot of interest. I have a mid-2011 27" that's exhibiting the same issues. I see your feedback about using the same size thermal pads; was that pad thickness? Are things still holding up well?

Andy Mumma - Reply

Thank you for this write up. I followed these steps and have a working GPU again. The Apple Store's quote was right at $650. I talked to 2 Apple Service Providers in the Dallas area and their quotes were even higher.

I was about to buy a replacement off eBay and install it myself when I came across this article. The system's been humming along ever since.

Wanting to keep an eye on the GPU's temp I installed iStat Menus. Then I searched around a bit to find what the optimal temps were during low use and high stress. I wasn't able to track down what it ought to be running at.

My numbers: Normal use it's running around 130°. Running Cinebench's OpenGL test it gets up to around 175°.

This seems high to me, but not sure. Thoughts? If this is running too hot, what can be done about it?

Matt

matt - Reply

Hi Sebastian,

I have the same issue on the very same iMac model and I want to try out your solution, which is both inventive and elegant at the same time :-)

Before I embark in this endeavour, I would like to ask you: did you use both thermal paste and thermal pads?

Do you remember how thick the thermal pads were?

I find on ebay/amazon/local shops several sizes and I can't figure out which one would be better suited (and looking at the video card doesn't really help, as they're pretty rough)

Alberto - Reply

Hi, I baked my graphics card and it powered up and ran fine until had it on full screen watching a youtube video. The graphics card gave out again, but my question is, do you think it's the heatsink that could be causing this graphics card to fail? I also would like to know if any of the fans work? I never hear them even in the slightest?

Pls advise

pcamac - Reply

Hi, Few months ago I baked my graphics card following all the steeps and it works. I couldn't really believe it, the imac was literally back on business, my only concern was when I tested the graphic card on games. The games aren't running smoothly as before, looks like when I'm playing the game freeze then continues and it's really annoying. I don't know if anyone here tested this into simulation games and if there is any possible solution knowing the card is already faulty.

Seb.

Juan Sebastian Toro - Reply

thanks for sharing this, works great for me to:)

the only problem i have is the fans that working non stop:(

osher sarfati - Reply

Thanks so much to everyone who has supported this post, just wanted to share my experience, I had one of the 2gb cards not working just the white screen while booting, after baking it the card is working like a charm, I also found a couple videos in YouTube of people doing the entire process and that helped me to get confident enough to do it.

Thanks again for this awesome post and believe it because it works.

PD. Does anybody know the science behind this trick? I mean why baking it brings it back to life? Who came up with this idea? Is it a pretty standard procedure on electronic boards?

Thanks again you guys..

David Guillen - Reply

I'm doing it now as well. Lol

Apparently the adhesive holding the chip in position giving in and therefore the chip looses the contact due to its upright positioning. And baking it laying down will heat up the adhesive and let the chip research correctly.

But then again that's what the guy on YouTube said. Lol

amasic -

I'll be damned, it worked. Thank you for saving me almost $400!

Travis Farmer - Reply

Thank you for this article, it gave me the courage to try it with my mid-2011 iMac that died this summer due to the 2G video card failing. A replacement video card from eBay was running $600-800, so that was a non-starter. Sure enough, 10 minutes at 400F brought it back to life and I’ve been using it for the past 6 weeks, running just fine! Two thumbs up! My only cost (besides the better part of a Sunday afternoon) was an “open an iMac” toolkit from Amazon.

Charles Walter - Reply

I came across this post and at first thought that it sounded a bit “out there”! I brought the iMac to the Apple Store this week to have a free diagnostic test done. I was informed that the video card needed to be replaced. With labor, the bill would have come to $937.00 (CDN)! Well, my buddy and I tried your fix on my iMac last night. to my utter joy and amazement, it works!! There truly are no words to express my gratitude!! Thank you! Thank you!

Kirk - Reply

iMac (27-inch, Mid 2011) AMD Radeon HD 6970M 1GB Burned on Micro Oven

Hi, I tried to heat Graphics Card on Micro Oven upto 200 degree celsius. Within few seconds some cracker sound occurred and then some capacitor is burned on Graphics card. I don’t know what is happened inside oven. I totally loss my Graphics Card.

Is it safest method to heat Graphics card on Oven?

Ramanan K - Reply

Hi,

I’m in BC, Canada. Mid 2011 iMac, AMD Radeon HD 6970M 2GB video card problem confirmed during a visit to local Apple Store. They had a free replacement program for those video cards but it expired after 4 years. Replacement cost CND $850 + tax. Next step - phoned Apple Care - they agreed to replace the card for free. Love Apple.

Swavik Ceglarek - Reply

When did you do this?

Pawel Pluta -

I was on the phone with apple yesterday. I have the same iMac and GPU. They will not fix mine :( I’m in Toronto. Any suggestions???

Nick Oz (Nick the Scuba Guy) -

I have the same iMac and GPU. Called applecare yesterday and they will not fix mine, citing the replacement program has expired. Am I missing something? I’m in Toronto.

Nick Oz (Nick the Scuba Guy) -

When I saw the headline I thought it was a joke but now I see you were serious. I have a late 2011 MacBook Pro with the infamous graphics card/soulder problem. The cheap @%^$$@$# in Tim Cook’s office refuse to fix it (again). My machine has been sitting at a third party repair center for 8 months. Do you think if I got the machine back that I could bake the MLB? Seems like the plastic parts would melt at some point.

spatterson - Reply

FYI .. the only part you would bake here is the graphics card — minus the heatsink and little bit of black insulation padding that is stuck on it … there’s no plastic to be worried about. What did you end up deciding to do ?

MikeH -

I did this about 4-5 months ago and the card worked until this week…. not a bad temporary repair, but I’m thinking these cards need to be redone with better (leaded?) solder. I’m not sure whether it’s worth trying again but we will see….

MikeH - Reply

well .. I decided to give another bake attempt a go. I was somewhat surprised to see that the machine is now working again (for 2 days so far) after the second bake. I’m sure it is not a long term fix so I’ll use this time to try and figure out what my plan might be for replacing the machine.

MikeH -

I just baked my iMac 27 Radeon M6770 512 yesterday. It is now at 24 hours and working flawlessly. I am very happy to have run across this thread! Assembly is not hard, re-sembly was the challenge. Anyone trying this use a little scotch tape to gather and control any wires/connectors that might fall down under the logic board when re-installing it. It will save many frustrations and get you up and running much faster!

Alan Larson - Reply

Hi Sebastian,

My 27” mid-2011 iMac has been exhibiting similar issues which prompted me to try your fix. I have proceeded Through the steps and am now ready to reassemble. I have, however, encountered an issue. There is a small, square, foam gasket that surrounds the housing of the GPU chip itself. After the many years of use, it became extremely frail and upon removal, ripped at one corner. Additionally, the two sided tape which held it in place has lost its sticky quality and will no longer hold the gasket in place. I have tried to research for a replacement but with no luck, as I have no real information about the part. I have contemplated continuing the rebuild without the gasket, but because I am unsure of its importance or function, I have not. I wonder if any of you have had a similar issue and know of a replacement/fix.

Thank you for your input! I am ready to have my Mac back again!

Graham Stewart - Reply

@mhren I notice that you referenced this part in your reply to Spatterson. Could you lend any assistance my way in regards to my above comment.

Thank you!

Graham Stewart -

Can’t believe it. It worked. I got my iMac back!

Some things I would point out that are not noted on here or you may miss.

On the video card is a sliver of foam that goes around some of the chips. The foam is not stuck to the board. It is stuck to a sticker that you can put a micro screwdriver under and pull up to re-use. I actually ruined and put my back together without it and it seems ok so far.

It is hard to see in the pictures but the card is suspended in air during baking. I did it by crumpling foil up into small squares and cut some slits into one side then slid the edges of the corners of the boards into them. That way the card sits level and is not resting on the tray while cooking.

I used the pads and thermal paste. Take a picture of where the old thermal pads were before you clean them off. I got some nice blue ones on Amazon. The 15mm x 20mm x1mm thick were perfect. They come in a sheet with plastic on both sides. Cut to size, peel one side and apply, peel the other and trim with razor.

Andrew - Reply

I fixed mine today, GREAT. Don’t forget to position USB ports in the back. First time I could’t plug the USB, so I had to correct the position of motherboard. Just put the usb plug before torque those screws on MB.

marcinq - Reply

Hi iFixIt!

I know this might be defeating the purpose of the site, but I am mechanically disabled, and for that matter, I’m actually disabled, C-7 quadriplegia. So my fingers don’t work great, constantly dropping screws etc. Does anyone live in/near New York City who has used this technique to fix their machine? I would be willing to work some sort of deal to hire you to help me fix my ailing machine.

Warmly,

Dustin Grella - Reply

When my 2011 Mac failed and eventually got diagnosed with “video card failed - vintage equipment - cannot be repaired” by a trusted service provider I started looking for a used video card. As a trained engineer, I must admit I was more than sceptical when I came across this “baking” fix but being faced with the choice of either binning a 2000€+ iMac and attempting a quick fix, I thought “what the heck”. So I ordered myself a 8,5€ tube of Arctic Silver paste and started to disassemble my iMac. After careful reassembly I powered up the Mac and SHAZAM ! … works like a charm. As I had everything taken out anyway, I used the opportunity to replace the thermal paste on the CPU as well, by the way.

Now, be aware that taking out the MB and reassembling an iMac is not for the faint-hearted. It does require some skill and patience (and a decent of tools, which you can get from iFixit or OWC) but in the end, it’s just one step up from swapping the HDD for an SSD, which you should do in any case !

philippe.bleiman - Reply

+1 from me also. Baked the AMD video card @ 200 C fan forced for 11 mins & revived the GPU.

Thanks so much.

Cameron

Cameron Brawn - Reply

Baked 2 AMD cards for my 2011 27” Imac A1312 and it worked like a charm.

Had to remove the logic board before I could remove the gpu so that was the most tricky part (lots of little connectors) , but baking at 200 degrees cel for 9 minutes, did the trick for me too!

raw - Reply

My iMac died on me a year ago and I’ve been meaning to do the card baking trick for months now. I finally found some time to give it a try and now my system is working again!

Unfortunately the fan seems to kick into high gear once I start doing any tasks, even just browsing safari. I’m wondering if it’s my fault for not applying new thermal past to the areas around the chip (I used the silver paste on the chip itself). I also dropped a tiny piece of masking tape inside the machine that I couldn’t find for the life of me, so I’m worried that sucker is doing some damage.

Anyway, I am happy the thing turns on at all and is usable.

V Spensieri - Reply

Hi

I baked my graphic card more than 4 times. unfortunately in my case, it does not works more than 2 or 3 weeks. GPU die is less than 60C and nothing wrong. I dont know what is wrong with that, any idea?

Mohsen Houshmand - Reply

Awesome! I’ve read about this fix and was hesitant to try it, but picked up some thermal paste and followed instructions. It’s really not that hard if you have the proper tools. Take a photo before you start to locate cables and screws, and take your time. I baked mine at 400 for 10 minutes and reassembled. Good to go. Thanks Sebastian.

hirezgraphics - Reply

Worked like a charm! I went to the Apple store to get mine tested and they wanted $550 to replace the graphics card. I started searching for used graphics cards and luckily stumbled across this post. I baked mine at 395º for 15 min. It has been running fine for the past month and a half. Thanks Sebastian for sharing this wild idea….my Facebook friends were in awe.

Mr. Meyer - Reply

Revived a co-workers 27-inch 2011 iMac last Friday. I’m skeptical how much longer it will run for and warned the owners it could fail again at any time. I also recommended that they run the fans at a higher rate to keep the machine cooler. I don’t have any experience using this utility, but its free so I recommended it:

++https://www.crystalidea.com/macs-fan-con...

Will try to report back if I hear more of this machine’s plight.

NorthernBigDummy - Reply

I did it. it works. I’ll keep the Macs Fans app active, but I plan on selling the iMac to help finance a Hackintosh.

rocksteadyhart - Reply

Thanks for this guide. I was able to revive a 27’’ iMac.

210 ‘C for 20 minutes did the trick.

Hopefuly this won’t change. I keep my fingers crossed.

Wolf-Dieter Rieck - Reply

Same here, thanks a lot! Reassembled the GPU board on the cooler with 1mm pads on the memory chips and a little good cooling paste on the GPU. Hope this will last for some time!

Mark Bakker - Reply

I can’t believe y’all are just throwing your GPUs into the oven. More so that it’s ACTUALLY WORKING for a SIGNIFICANT amount of people. Maybe baking electronics should be used more mainstream as a fix for other defects?

Liam - Reply

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