Display Bios to external Monitor at System Start

Recently, My laptop lcd got broken after a fall so I unplugged it from the motherboard. I am trying to connect it with an external monitor but unable to get my bios display onto external monitor. I tried FN+F1 which is external display function key on my keyboard. Monitor light turns to blue which shows it is attached but it stays blank. I have bios password setup. Wonder, That is making an issue here?
Please advise, I am unable to search a solution for this specific case. Laptop is Dell Inspiron 3537.

Solution 1:

From the Dell community: "The system will not complete POST without a working internal screen attached. You will need to replace the display panel."

That said, if you plug in the display again, the OS might not "know" it's broken and POST (though hidden). If it's just the back-light that's broken, you might be able to see a very dim, grayish, display without it, and back-lights are usually more easily replaced.

Also, F4, with or without Fn, might be the key to press for an external monitor on the Dell 3537.