For the laptop to function you can't remove the laptop display. There is no support for such a configuration.
So I have an old Dell XPS 14z and decided to rip it apart and build a tiny fancy pc tower with the motherboard to use with my TV. I decided I have no use for the built-in screen, so I disconnected it from the motherboard.
When I keep the TV connected via HDMI, upon boot the TV shows nothing (no matter how much time I allowed).
When I reconnect the internal monitor on the motherboard it's working.
When I connect both the TV and the screen, it's also working. (That's true even if I only connect the video cable, leaving the built-in screen's inverter disconnected)
When I connect no display at all, and then connect the HDMI TV a few seconds after boot, I get the black screen with the underscore.
Is there a way to make the motherboard forget it used to have a laptop screen and go directly to HDMI? Would that work better if I used a VGA cable? (There's no VGA port on my motherboard, only HDMI and Mini Display).
Any help is greatly appreciated. I really don't wanna end up keeping the built-in screen, it messes up the whole aesthetic.

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