Question: Replacement Graphics Process for Mid 2011

[arcsound]

I just performed the oven bake on my HD6970 graphics card inside my mid 2011 iMAC, and it worked! Pink bars gone, and machine booting again, this fix really works! At least temporarily... From what I understand, the failure will come back, maybe in a few months, maybe after some years, but it will return.
I'd like to get a replacement graphics card, but they are fairly $$$, and how do I know if has been refurbished or a fake? One E-Bay seller posted this information, however, which claims that AMD came out with a chip in 2016 that finally addressed the problem, but any 2017 or 2018 versions are Chinese fakes. Can anyone verify if the Seller's information below is accurate, i.e. that I should be looking for an HD6970 with a 2016 processor? Thanks in advance! :
APPLE AMD RADEON HD6970 2GB For iMac 27" 2011 (2009-2011)
These cards have New Original AMD CHIP from 2016 year

Only in this year (2016) AMD produced chips without a defect. Chips from the years 2017-2018 are Chinese fakes.


We say NO to chinese repair chip (2010-2014), that work 1-3 months. If you want to have a good iMac forever, you need this card

 

[herrdude]

Do not bother with those cards. Visit this thread which explains how to install other cards that will allow you to have Catalina as well:

2011 iMac Graphics Card Upgrade

iMac 2009 to 2011 MXM3 graphics card upgrade (Lastest update 10/13/2023 - this is the official documentation page - you found it finally!) This is the single and only documentation post. During the last years we constantly updated this post to reflect the lastet development of vBIOS and OCLP...

forums.macrumors.com

 

[arcsound]

Do not bother with those cards. Visit this thread which explains how to install other cards that will allow you to have Catalina as well:

2011 iMac Graphics Card Upgrade

iMac 2009 to 2011 MXM3 graphics card upgrade (Lastest update 10/13/2023 - this is the official documentation page - you found it finally!) This is the single and only documentation post. During the last years we constantly updated this post to reflect the lastet development of vBIOS and OCLP...

forums.macrumors.com

Interesting alternative, did not realize this was an option. Do you know if any of these options are super easy, i.e. swap cards, power up....? Reading the FAQ, this one gave me pause:
Not necessarily. This "fix" is more of a "mod" to revive our iMacs. Depending on your scenario, it requires full iMac disassembly, knowledge of VBIOS flashing, dremel tools, heatsink modification, careful handling of logic board components, etc. With the used/grey market for many of these cards, other issues may pop up as well. Please be cautioned before undertaking this process.
I don't mind the full disassembly, as I lived through the bake process, which did require a full tear down with my version iMAC, but the VBIOS flashing and heatsink mods sound too much like a science project for me.
Perhaps there are some local SME/Gurus that are comfortable with this process, need to make some inquiries.
Thank you for these options!

 

[herrdude]

Interesting alternative, did not realize this was an option. Do you know if any of these options are super easy, i.e. swap cards, power up....? Reading the FAQ, this one gave me pause:
Not necessarily. This "fix" is more of a "mod" to revive our iMacs. Depending on your scenario, it requires full iMac disassembly, knowledge of VBIOS flashing, dremel tools, heatsink modification, careful handling of logic board components, etc. With the used/grey market for many of these cards, other issues may pop up as well. Please be cautioned before undertaking this process.
I don't mind the full disassembly, as I lived through the bake process, which did require a full tear down with my version iMAC, but the VBIOS flashing and heatsink mods sound too much like a science project for me.
Perhaps there are some local SME/Gurus that are comfortable with this process, need to make some inquiries.
Thank you for these options!

The thing is the amount of work in installation is the same as replacing the card. You do have to reprogram the video card by either getting a chip programmer from Amazon for $10-$15 OR installing the card into the iMac and creating the Linux bootable USB from the thread and running a few lines from the command line to upgrade the BIOS. My feeling is that if you can take apart and reassemble an iMac this extra step is negligible. Not all the cards require a heat sink mod. K1100m and K2100m are the best choices. The other cards are more powerful and as such you would need to modify the computer.

I installed the K2100m which had 2GB and my old card had 512mb. Much more memory and Catalina for really not much more effort than a stock card. Feel free to ask any other questions you may have.