HP Envy x360 - Broken LCD, Boot with HDMI external display only?

[CGG23]

Hello,

I recently purchased a damaged HP Envy x360 Convertible Laptop, Model: 15-bq003AU. 

It has a smashed screen and I was hoping to replace this.

Both the m.2 SSD and the SATA SSD were removed when I received this, and I connected a SATA SSD with Windows 10 pre-installed on it.

I have completely disconnected the original screen.

I have powered it on using an HDMI cable to a Monitor, but can't get any display signal at all.

I have tried using the FN + F4 command without success.

I'm assuming that I need to get into the BIOS and change the bootable drive from the M.2 SSD to the SATA SSD?

I plan on installing a new screen, however I am reluctant to outlay the cash for that before knowing everything is working as it should.

Any hints, tips or tricks would be appreciated.

Thanks.

[WAWood]

@CGG23 

Sorry, but you're not going to be able to do that.

The HDMI port is not enabled for display until after Windows starts and loads the video driver for it -- and since BIOS work is before that, there is no driver being loaded to enable the HDMI port.

This is one of the main reasons you can't use an external monitor as a replacement for the build-in display on a laptop.