After upgrade from 22.04 LTS to 24.04.2, second monitor won't function

[stevecoh1]

Ubuntu Version:

24.04.2 LTS

Desktop Environment (if applicable):

Gnome

Problem Description:

Some of you will remember me from a few months ago when I created this thread that turned into a barn-burner:

Which NVIDIA driver on newly upgraded Lenovo Laptop

Ubuntu Version: 24.04.1 Desktop Environment (if applicable): Gnome Problem Description: After a lengthy and difficult but ultimately successful attempt to upgrade to 24.04.1 a new laptop that had been shipped with 22.04, a question in regard to graphics cards arose. I chose to move this further discussion from Lenovo Thinkpad P16 Gen2 laptop won't accept 24.04 - #58 by oldfred to this new topic. Relevant System Information: Lenovo ThinkPad P16 Gen 2 RTX 3500 Ada Generation Laptop GP…

In the interim, Lenovo support presented me with a recommendation to try which appears not to have helped. Actually it hurt. It got me to 24.04.2, but with the same goofy proprietary driver that cannot be changed via the GUI. Additionally, my second monitor no longer works. The Displays tab of the Settings app sees the second monitor but does not allow me to activate it.

I am trying to decide whether I should roll back to 22.04 again as we concluded the last time or soldier on with 24.04 if I can fix the 2nd monitor issue.

So my question for now is simple:

What command line/config file options are there for debugging/fixing the 2nd monitor issue?

I also provide below one possible clue: differences between nvidia-smi output between January and now.

Relevant System Information:

Screenshots or Error Messages:

Screen shot of Gnome Settings Displays tab

Notice that although the second monitor (BenQ Corporation 24") is visible to the system, it cannot be activated. The Join button is greyed out. I can click on the arrow to the right of “2: BenQ Corporation 24” and click the slider there to “enable” it and then the Apply button, but this achieves nothing.

It does not activate the second monitor.

Below is a link to the output from the nvidia-smi command from January and the output now, which shows a significant difference.

January nvidia-smi output

nvidia-smi output today:

$ nvidia-smi
Thu Apr 10 12:49:11 2025       
+---------------------------------------------------------------------------------------+
| NVIDIA-SMI 535.183.01             Driver Version: 535.183.01   CUDA Version: 12.2     |
|-----------------------------------------+----------------------+----------------------+
| 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 RTX 3500 Ada Gene...    Off | 00000000:01:00.0 Off |                  Off |
| N/A   39C    P8               5W / 115W |      6MiB / 12282MiB |      0%      Default |
|                                         |                      |                  N/A |
+-----------------------------------------+----------------------+----------------------+
                                                                                         
+---------------------------------------------------------------------------------------+
| Processes:                                                                            |
|  GPU   GI   CI        PID   Type   Process name                            GPU Memory |
|        ID   ID                                                             Usage      |
|=======================================================================================|
|  No running processes found                                                           |
+---------------------------------------------------------------------------------------+

Note that in January there was an XOrg process running on the GPU. In today’s output there is no process running on it. This looks like it might be significant. Is it?

Is there any way to debug and fix this?

Or would I be wiser to bite the bullet and go back to 22.04 LTS again?

What I’ve Tried:

---

[ogra]

@stevecoh1

In the interim, Lenovo support presented me with a recommendation to try which appears not to have helped. Actually it hurt. It got me to 24.04.2, but with the same goofy proprietary driver that cannot be changed via the GUI

Can you elaborate on this? What exactly did they tell you, what did you use to get into that situation again…

[stevecoh1]

@ogra

Can you elaborate on this? What exactly did they tell you, what did you use to get into that situation again…

What they told me was vague and I am angry with myself for believing it. They had done “something” to resolve the issue and I should try again. It had none of the specificity of our discussions here 2 -3 months ago which I reread before sending this. If I could talk with actual engineers it might be fruitful but everything is filtered through this well-meaning but clueless “support rep”.

I raised this again for the specific purpose of finding out what might be the cause of the non-functionality of the second monitor.

If no one can help with that, I will most likely restore 22.04 and go from there.