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Joeytino

macrumors newbie
Original poster
Dec 11, 2020
7
0
As the original 6770M joined the pile of failed graphics cards, I upgraded my iMac 12,2 i7 two years ago with an AMD WX3200 already flashed with Apple firmware by the seller and using Open Core and had zero issues. Last month I built an OCLP Monteray USB on another iMac and added the Polaris option but no display after upgrade unless I boot with the OC-CD the seller of the card gave me and that wakes up the display and everything works. I try to install the proper EFI, but it does not work, and it even appears that after reboot, OCLP does not detect that the EFI partition was supposedly rebuilt. Even if I pull the drive and connect it to my other iMac and attempt to rebuild the EFI, it fails to activate the display. What am I missing? Is there any way to resolve this or just easier to back up and start over?
 

Nguyen Duc Hieu

macrumors 68040
Jul 5, 2020
3,016
1,003
Ho Chi Minh City, Vietnam
Your card came with a customized EFI by the seller.
Unless you are familiar with OC settings like kexts injecting and config.plist file editing etc, I would suggest you try the following to see if it works.

1. Insert both the OC-CD and the USB installer to iMac
2. Boot and press C to order to iMac to boot from CD.
3. If the OC menu pop-up (it should), then select the USB installer.
4. After the iMac booted from the USB installer, you can now install Monterey
5. On the first reboot, still press C to boot from OC-CD; then select the internal SSD (newly installed Monterey)
6. If your iMac boot to Monterey desktop, then overwrite the EFI volume of OC-CD to the EFI volume on the internal SSD.

If it doesn't work, contact the seller to cook a new OC-CD disk image for you, insisting that it must be compatible with Monterey. You can download it and burn it to a new CD-R to use.

Note: The above instruction was based on my assumption that you know how to work with the hidden EFI volume on various media. If that's not the case, disregard the whole instruction above.
 

Joeytino

macrumors newbie
Original poster
Dec 11, 2020
7
0
The seller is long gone from eBay so not an option. I could never get the display to work on boot without the CD, so what I did was booted with it, unhid the EFI partition with Hackintool, and copied over a new EFI I created on a USB stick. That allowed me to boot normally from the internal drive and I was able to re-run OCLP but now I am suddenly missing bluetooth and sound - wifi works - even though they worked fine before. I did run the post install patches without any luck. I will keep an eye out for a more compatible GPU when I get the chance to make my life a little easier. Thank you for the suggestions.
 
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