That *&*%@?!5 GPU card!!!
The MacBook Pro with the dodgy GPU, well, it decided to update itself again, with meant it wouldn’t boot. I did have a look online to see if there was a permanent fix, the only way to do that was to do something with a soldering iron, I thought it was best to steer clear of that. I did train in electronics, but I am rubbish when it comes to physical practical stuff. I would prefer if it could be done programmatically.
This time I missed a few parts. In total, it only took about five minutes to fix it.
So how did I do it I hear you cry, good question, here is the answer…
If you having problems seeing the screen, boot into single user mode but holding down command and S when you boot the machine up.
Run
nvram fa4ce28d-b62f-4c99-9cc3-6815686e30f9:gpu-power-prefs=%01%00%00%00
Reboot. On the reboot, hold down command and R when you boot the machine up, let go when you get the Apple logo.

Click on utilities and terminal:

If you have more than one partition run the following lines, if you only have one partition you can skip this bit, but we need to find the UUID:
diskutil cs list
diskutil coreStorage unlockVolume UUID
Now, we all need to do the following, run the command:
cd /Volumes/Macintosh\ HD

Now, we need to remove the AMD Kexts, first create a directory where we can stick them on the off chance you need them in the future using the line:
mkdir AMD_Kexts
Because I had done this a few times, I have now started to create the directory on the date, so this one I called 12Jun21_AMD_KEXTS
Now, lets move those AMD Kexts:
mv System/Library/Extensions/AMD*.* 12Jun21AMD_Kexts/
then type in reboot:
reboot
In theory, if you have done everything correctly, you should now have a working MacBook Pro.
I booted, and it worked!

But the question is, will it reboot OK. It did. So I will shut down and leave it and take back to the owner tomorrow. I think if it keeps doing it I will suggest he buys a new one, it is 10 years old now.