Hi all! I am trying to upgrade my GPU with a Dell Nvidia GTX 770M. (VBIOS: 80.06.60.00.01) on my iMac 21.5 Mid 2011 (EMC...

I know this is from years ago but I have been working on this recently and finally solved the issue, bringing my SSD back to life. Let’s start by defining the issue: it is a common problem with old SSDs using SandForce controllers. Because of incorrect instruction management, these occasionally freeze up and deny system detection. The only thing that you may see if a ~30kb drive named SandForce{200026BB} , either in the BIOS or in the System Report. What you have to do in order to solve it is pretty lengthy and complex, and you will not be able to save the files you have on your SSDs: it will all be gone. Having this in mind, I wouldn’t personally proceed unless you are very eager to bring your SSD back to life as a new drive. Before starting this procedure, you can always try to forcefully issue some SATA wakeup commands to the SSD, by plugging it in a PC (You need a BIOS) and performing the following steps: (1) Leave everything shut down for 2 minutes (2) Boot and head straight to the BIOS, where you...

For ANYBODY experiencing this: What happened was that even if the Dell VBIOS is supposed to work on iMacs, mine was for some reason not UEFI ready. It is not a big deal as it will be detected anyways from the motherboard, and most importantly from nvflash, which you’ll use to flash your GPU and make it UEFI-useable. So, if you experienced this, follow these steps: (1) Get yourself a 32GB USB or (preferrably) a hard drive/ssd that you can connect via USB. (2) Using Disk Utility on Mac, erase it (Use Journaled FS) (3) On a Windows Computer or virtual machine, download the software “WinToUSB” (you NEED the enterprise version) (4) Using disk management on that Windows computer, select the primary partition of your external drive, and right click > Delete Volume (5) On the erased space, right click > Create new simple volume (6) Just go ahead with default options and make sure the file system is NTFS (7) Download a Windows 10 ISO (8) Open WinToUSB, select the ISO you’ve downloaded, next select your external hdd...