iMac 2011 27" GPU changed to Nvidia 1060 Modbile: no more internal monitor (linux)

I have a iMac 2011 27" and I decided to change my video card from Nvidia k3100m to Nvidia GTX 1060 Mobile. You can see down there the result of “uname -a” and of “nvidia-smi”.

Now, everything is working EXCEPT the internal monitor.
I’m now writing from my external monitor connected via Thunderbolt port with an HDMI converter, so the video card is working and is shown.

At bootup the monitor stays completely black while with the K3100M it starts as white and then follows the boot process normally.

Right now the partition table is the following:

Dispositivo Start Fine Settori Size Tipo
/dev/sda1 4096 618495 614400 300M EFI System
/dev/sda2 618496 1935070163 1934451668 922,4G Linux filesystem
/dev/sda3 1935070164 1953525101 18454938 8,8G Linux swap

Now, i know that there are some “compatibility” issues with Nvidia cards and EFI system of MacOS, but the EFI partition should be linux now, isn’t it?

To be right, at startup even GRUB is not displayed (one, while dual booting, I had reFind installed) but when I resinstalled Linux only I neve saw reFind boot again, just straight to (i think) first option of grub).

What can i do to allow the video card to be seen again by the internal monitor?
Thanks a lot.

Linux francesco-imac122 6.14.6-2-MANJARO #1 SMP PREEMPT_DYNAMIC Wed, 14 May 2025 14:56:34 +0000 x86_64 GNU

It says “Firmware Version 87.0.0.0.0”

Mod edit: removed screenshot of text. Please see post below.
➜  ~ nvidia-smi            
Sat Jun 14 16:56:14 2025       
+-----------------------------------------------------------------------------------------+
| NVIDIA-SMI 570.144                Driver Version: 570.144        CUDA Version: 12.8     |
|-----------------------------------------+------------------------+----------------------+
| GPU  Name                 Persistence-M | Bus-Id          Disp.A | Volatile Uncorr. ECC |
| Fan  Temp   Perf          Pwr:Usage/Cap |           Memory-Usage | GPU-Util  Compute M. |
|                                         |                        |               MIG M. |
|=========================================+========================+======================|
|   0  NVIDIA GeForce GTX 1060        Off |   00000000:01:00.0  On |                  N/A |
| N/A   41C    P8              5W /   78W |     550MiB /   6144MiB |      1%      Default |
|                                         |                        |                  N/A |
+-----------------------------------------+------------------------+----------------------+
                                                                                         
+-----------------------------------------------------------------------------------------+
| Processes:                                                                              |
|  GPU   GI   CI              PID   Type   Process name                        GPU Memory |
|        ID   ID                                                               Usage      |
|=========================================================================================|
|    0   N/A  N/A            4794    C+G   ...b/gnome-remote-desktop-daemon         63MiB |
|    0   N/A  N/A            4821      G   /usr/bin/gnome-shell                    207MiB |
|    0   N/A  N/A            5214      G   /usr/bin/Xwayland                         1MiB |
|    0   N/A  N/A         1827478      G   /usr/lib/thunderbird/thunderbird        174MiB |
|    0   N/A  N/A         1863007    C+G   /usr/bin/nautilus                        29MiB |
|    0   N/A  N/A         1863073    C+G   /usr/bin/gnome-text-editor               28MiB |
+-----------------------------------------------------------------------------------------+

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