Taken from 2011 Macbook Pro Graphics Card FIX 100% WORKING!!!
EDIT This method works! But there is an improved version for better thermal management and brightness keys functionality. See improved version -> https://gist.github.com/cdleon/d1eff7246a25193304284ecec40445b0
if you are on high sierra 10.13.6+ you might need to use
Command + rinstead
Boot up holding down Command + r + sSIP locks System folder so cannot move kexts to another folder. SIP (csrutil) only enabled or disabled on Recovery Mode.
csrutil disablerebootboot up holding down the CMD and S keysuse /sbin/fsck if you get fsck command not found
fsck -fyuse /sbin/mount if you get mount command not found
mount -uw /sudo mkdir /AMD_Kexts/sudo mv /System/Library/Extensions/AMD*.* /AMD_Kexts/sudo rm -rf /System/Library/Caches/com.apple.kext.caches/sudo mkdir /System/Library/Caches/com.apple.kext.caches/sudo touch /System/Library/Extensions/Unmount a partition to guarantee that your changes are flushed to it. Use /sbin/umount if you get umount command not found. It might say resource busy, ignore that and proceed to next step)
sudo umount /sudo rebootBefore enabling SIP again, try the normal boot without pressing any key. The Mac OS will rebuild the kernel cache and restart. See if the system starts normally. If it does, still keep going through the remaining steps.
You might encounter that you are still using discrete GPU but computer works (if you are using gfx it might say can't change to discrete while external display is connected), keep going until last step and this will be resolved
if you are on high sierra 10.13.6+ you might need to use
Command + rinstead
Command + r + scsrutil enablerebootsudo nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00sudo shutdown -r nowYou might need to do this again after macOS system updates Brightness keys might not work use app like brightness-slider to handle that
Strongly recommend against upgrading past your model’s maximum Apple recommended OS. While it can sometimes be done, it’s fraught with potential issues. Given you need help with your current problem, I wouldn’t even consider it. Besides, you want to resolve your current issue, not add additional problems.
Try following the instructions on Apple’s webpage:
https://support.apple.com/en-us/HT204904#:~:text=Command%2DR%3A%20When%20you%20press,is%20compatible%20with%20your%20Mac.
If you’re able to enter recovery mode, that’s your best option. You want to first try reinstalling your OS without wiping your drive. If you can’t get into recovery, try the options for reloading your OS. If given the choice, don’t wipe your disk. If you’re unable to resolve your problem without first wiping the disk, that’s your final option. Hopefully you have backups to restore your user data. But if you have no backups, and desperately need the data on your computer, all of this is potentially risky. Instead, remove the drive and put it into a USB case. Try to extract the data from the drive that way, using a second Mac, rather than trying to fix your boot issue.
P.S. It’s possible you might be able to extract your user data using a second Mac via Target Disc Mode, if you have access to one. If you borrow/buy a newer Mac, and target disc mode won’t work, remove the hard drive from the old one, and put it into a USB case. Then extract the data you need that way. Note: Using target disc mode requires cables and pricey adapters you likely don’t own, and probably won’t use again.
Good Luck!