iMac 2011 white screen after boot

[Sprechender]

I bought an iMac 2011 about 2 weeks ago and it worked perfectly fine in safe boot but couldn't boot normally.
Changed the drive formatted installed and still couldn't boot without safe boot.
It runs macOS Lion.
In verbose boot it is so fast I can't read it.
Then just white after about a minute it gets a little darker but I think it's something like standby when I move my mouse it goes back to white and the cursor appears.
How can I fix this?

Tried High Sierra and Sierra which it supports and there is a error that goes like "gIO Screen Lock State 3" where it completely stops booting and just freezes

 

[trs96]

"gIO Screen Lock State 3"

This indicates a graphics problem.

The 2011 iMacs were notoriously problematic, having frequent AMD graphics card failures. Determine if it's a problem first by checking diagnostic LEDs. It's one of the reasons Apple switched back to Nvidia dGPUs for a short while in 2012/13.

If the graphics card must be replaced and you don't know how to do it yourself, I'd suggest an Apple repair shop. Lots of things can go wrong when taking out the whole logic board and doing this.

 

[Sprechender]

This indicates a graphics problem.

The 2011 iMacs were notoriously problematic, having frequent AMD graphics card failures. Determine if it's a problem first by checking diagnostic LEDs. It's one of the reasons Apple switched back to Nvidia dGPUs for a short while in 2012/13.

If the graphics card must be replaced and you don't know how to do it yourself, I'd suggest an Apple repair shop. Lots of things can go wrong when taking out the whole logic board and doing this.

If understand correctly the third diagnostic LED means the GPU can communicate with the Logic Board.
Every LED lights up except the fourth but that is normal because I have the screen not plugged in.
Do you know what could be the error and thanks for the info with the LEDs?

 

[trs96]

Do you know what could be the error and thanks for the info with the LEDs?

The verbose output says it's something graphics related. That's all I can say for certain.
I would try making a USB boot drive with OpenCore legacy patcher and see if that has the same problem.
You don't have to use something as new as Ventura or Sonoma. Start out with Big Sur and see how that goes.

OpenCore Legacy Patcher

Experience macOS just like before

dortania.github.io