Booting my Dell laptop without internal display connected

[link6155]

Hey everyone,

 

So I've been working on a project where I'm using an eGPU with my old Dell Inspiron 17r-5720. I was able to set up an AMD GPU easily, but I couldn't get a GTX 960 working on it. Because of this, I can not take advantage of Optimus (allowing you to use built-in laptop display with external graphics). So I've concocted up a plan to work around this. I want to hook up my GPU directly to my laptop monitor so I can take advantage of the eGPU without an external monitor.

 

So here's my problem. My laptop refuses to boot up with the display disconnected (I get the 8 beep error code which means display error). Does anyone know how I can get around this?