Replace AMD Radeon 6770M in 2011 iMac 21.5

Nothing new is available. You will be shopping for a used/pulled card.

The problem is the cards have been hard to find and, when you find one, expensive.

You can check powerbookmedic.com but last I checked, they were out of cards for 2011 iMacs.

Just checked—out of stock for both new and used ones:

https://www.powerbookmedic.com/Intel-iMac-215-ATI-Radeon-HD-6770M-512MB-Video-Card-p-66066-o-6690.html

⚠️ NOTE: Be careful when shopping. The card for the 21.5-inch iMac is physically different from the more powerful cards that came in 27-inch models that year.

As even a used card will cost more than a 12-year old iMac will sell for, you may wish to add a Plan B. You could likely buy a working 2011 of the same model cheaper that buying a card. Then there is the Augean task of installing the card. It is not a trivial matter.

Finding a new replacement 6770M for a 2011 21.5" iMac is virtually unheard of. Please remember the computer is 13 years old and is quite obsolete. While yes, the GPU is the only failed part right now, how soon will it be before your internal storage fails or something else? If you do manage to fix it you will have invested money in machine that has:

• <$100 in value

• Cannot run current versions of Mac OS

• is functionally and technically obsolete.

You may want to consider replacing the computer with either a new Mac, an Apple refurbished Mac or if $$ is a problem, a high quality used Mac from a reputable reseller such as Macsales.com.

In short, you have a variety of options available to you, some you may not have considered.