Stuck in boot loop, can't access BIOS on external monitor, laptop still detects internal display even after removing LCD screen from mother board

Its an old laptop:-Samsung NP300E5Z-S0AIN with broken screen having dual boot.

It goes into boot loop when I remove bootable linux usb and try to boot from interal hard disk(SSD).

Although the internal SSD is working because I can access it when I boot using live usb.

With the help of live usb I backed up data from SSD and formated and reinstalled linux but still it goes into boot loop that is it starts and restart just after loading BIOS.

Can't see the BIOS but can tell because on pressing F2 the fan slows down and pressing F10(save and exit) after it the fan keeps on starting and stopping.

I have detached the laptop's screen completely from motherboard but still when I boot from live usb linux it shows two displays in setting.

Tried:

• Reinstalling Os
• Disconnected internal screen from motherboard ie not even connected to hinges.
• Tried with windows bootable usb (but only worked with linux)
• CMOS battery removal and let the remaining charge get drained by long pressing power button after removal.
• closed lid to let the bios appear on external monitor and used magnets wherever the screen bazel touches when closed.
• Fn+f4 to move display to other monitors when entered Bios setup after pressing F2 on boot.

Trying to flash bios but need to use windows for that.

But main question is how can I completely disable laptop's own display so that it don't even detect it and defaults to external only. So atleast I can see current Bios setting, if something can changed to prevent boot loop.

old laptop:-Samsung NP300E5Z-S0AIN with broken screen

But main question is how can I completely disable laptop's own display so that it don't even detect it and defaults to external only. So atleast I can see current Bios setting, if something can changed to prevent boot loop.

You cannot substitute an external screen in most laptops (95% plus) and so you will need to replace the screen, or probably better, replace the aging laptop.