Unable to get second display to work using HDMI port, 2 gpus

I have a computer that has an HDMI port on the back for a second monitor. I have tried to plug in this monitor using this port.

I have assigned removed the NVIDIA GPU from dom0 and use another GPU for that. Is this why this is happening?

Is there a way to determine if this port is linked to the NVIDIA GPU?

there could be a pass threw issue I would suggest looking up info on gaming on Qubes and direct pass threw of a GPU for documentation.

That should be enough to get you to enough knowledge to at least diagnose the problem. I personally run two monitors but I let Dom0 handle all those display functions. An it does it seamlessly. I mean whats your use case? If your isolating a gaming system. If your just looking for a second monitor to be productive.

That said I’ve never done pass threw for gaming So IDK.

This didn’t help. When I run lspci in dom0 I see many things and don’t know if HDMI port is blocked somehow.

Would I use another command to see the port in dom0?

did you assign the other GPU to a different qube. For simply checking what GPU owns the port. Frankly I would open the box.