NVIDIA and Zorin 17.1 Lite: KERNEL upgrade issue

Hello All,
I have upgrade my mid-2009 Macbook pro from Zorin 16.3 CORE to Zorin 16.3 Lite to Zorin 17.1 Lite:

No problems so far with the Lite version, but since a recent OS update, I've noticed that I can no longer control the brightness of my laptop screen, whereas it used to work.

Also, the output for an external screen doesn't seem to work any more either.

I have the impression that the problems are due to the installation of the new Linux kernel.

For information, I have an NVIDIA C79 GeForce 9400 graphics card which should be using an NVIDIA 340 driver.
However, I think that the NVIDIA driver is not installed and that since I am on KERNEL 6.8.0-40-generic, the graphics card is badly managed, which causes the bugs described above.

Here is my HW probe:

You can see on this page that C79 is known to have a problem:

Where it is indicated that the graphics card is managed up to KERNEL 6.3 with the ‘NORMAL’ driver and the ‘NVIDIA’ driver but it is indicated FAILED with ZORIN 17 and WORKS with ZORIN 16...

Frankly, I don't know what to do now and I have a few questions:

  1. why is the NVIDIA 340 driver not proposed in the list of proprietary drivers? (this is an old problem I observed after upgrading to Zorin 17)

  2. I noticed in the past that when I tried to install this NVIDIA 340 driver on ZORIN 16.3, I had a black screen after the reboot and then nothing...
    So I don't know if I should really bother installing this NVIDIA 340 driver or not. For the record, I don't play games.

  3. Now that I have Zorin 17.1 LITE and the KERNEL 6.8, how can I adjust the brightness of my screen and still use the external screen, etc.?
    I have the impression that XFCE does not offer the same settings as GNOME.

What is your recommendation please ?

Thanks for your help.

The Driver isn't even available in the Repo's. You could try it with the 390 Driver instead if you want. But You could maybe have a Problem with the Kernel and that it is too new for the Driver.

Thanks Ponce-De-Leon,
I am not sure if I should install the NVIDIA driver because the last time I tried to install it with Zorin 16.3, I saw a black screen after the reboot and no way to extract from this situation. So I re-installed the OS and didn't change the default driver. I saw in this forum that is probably linked to a security boot issue that should be modified.

After the migration to Zorin 17.x, the option for upgrading the NVIDIA driver is not anymore visible.

Perhaps the best option for me is to downgrade the KERNEL to a previous version ?
For example the KERNEL 6.3 seems to be compatible with my graphic card.
Sorry for this question, but I don't know the procedure for downgrading the KERNEL. Any guidance will be helpful.
I saw this post with a similar issue than mine:

thank you :slightly_smiling_face:

This procedure worked for me from the Tutorial Section here on the Forum:

You mean in the ''Additional Drivers'' Tab in software & Updates? Is there no Nvidia Overview or or is there the Overview but the Options are greyed out and it is chosen the last Option which says that You use a manually installed Driver?

Yes, You could try it with that. The last Comment of this Thread explains it:

Hellon Ponce-De-Leon and zGnOmaha,
thanks for your help.

Correct: there is no NVIDIA overview. I see the BROADCOM DRIVER for the WIFI but no optional driver is proposed for NVIDIA since I have upgraded to ZORIN 17.
I remember that in ZORIN 16, it was possible to select the proprietary NVIDIA driver but I got a black screen after the installation and the reboot...and didn't know at this time how to extract from this situation (the grub menu was not visible and I have 2 os: MacOS and Zorin).

Yes, I have just updated the thread with a question to ThePhantom.