Hi @Jeremy Carr ,
A closed lid should force the output to the external monitor.
Most laptops detect a closed lid with a magnet and a sensor. There is a small magnet probably somewhere on the top edge of the screen, and a sensor in the area of the body of the laptop that it would be near when closed.
You can also try removing the bezel off the screen and this will disconnect the laptops monitor. This forces the computer to use the external monitor and shows the bios menus.
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