How can I use a second monitor via HDMI port?

If you still have the video-nvidia-450xx installed, what does xrandr print?

I see thanks for catching thatā€¦I changed my config but the results were the same (blank screen on my laptop & no output on the monitor)

Section "ServerLayout"
    Identifier "layout"
    Screen 0 "intel"
    Inactive "nvidia"
    Option "AllowNVIDIAGPUScreens"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1:0:0"
EndSection

Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
EndSection

Section "Device"
    Identifier "intel"
    Driver "modesetting"
    BusID "PCI:2:0:0"
EndSection

Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection

I got the bus-id from inxi --full -verbosity=7 (hope that is right)

Device-1: Intel HD Graphics 630 vendor: Dell driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:591b 
           Device-2: NVIDIA GP107M [GeForce GTX 1050 Mobile] vendor: Dell driver: nvidia v: 450.66 bus ID: 01:00.0 
           chip ID: 10de:1c8d 
           Device-3: Sunplus Innovation Integrated_Webcam_HD type: USB driver: uvcvideo bus ID: 1-12:5 chip ID: 1bcf:2b95 
           Display: x11 server: X.Org 1.20.8 compositor: kwin_x11 driver: modesetting,nvidia 
           alternate: fbdev,intel,nouveau,nv,vesa s-res: 3840x2160 s-dpi: 96 
           OpenGL: renderer: Mesa Intel HD Graphics 630 (KBL GT2) v: 4.6 Mesa 20.1.6 direct render: Yes

Sorry I switched to prime so I donā€™t have video-nvidia-450xx installed. I also donā€™t seem to have xrandr installedā€¦

This should be BusID "PCI:0:2:0".

Then install it: sudo pacman -Syu xorg-xrandr.

I see, thank you for correcting the busID

But this gave me the same result (blank screen)

Section "ServerLayout"
    Identifier "layout"
    Screen 0 "intel"
    Inactive "nvidia"
    Option "AllowNVIDIAGPUScreens"
EndSection

Section "Device"
    Identifier "nvidia"
    Driver "nvidia"
    BusID "PCI:1:0:0"
EndSection

Section "Screen"
    Identifier "nvidia"
    Device "nvidia"
EndSection

Section "Device"
    Identifier "intel"
    Driver "modesetting"
    BusID "PCI:0:2:0"
EndSection

Section "Screen"
    Identifier "intel"
    Device "intel"
EndSection

So you didnā€™t get any signal anywhere? Neither on monitor nor on laptop screen?
(Also: the 450 series is pretty new and still has some issues and why I asked you to install the 440 series as your GTX 1050 is supported by that one)

:man_shrugging:

Can you get the Xorg logs? Log into a tty, and then run startx -- -logverbose 10, and if it fails, check the files in ~/.local/share/xorg/.

I am starting to think that something is wrong at a basic levelā€¦because when I boot into windows 10, I canā€™t even mirror my display thereā€¦

Sure I will try that today after work, and update you guys - thank you for the follow up.

Smells like a hardware errorā€¦