BIOS works, but doesn't show?

[AdamJames12]

So I'm currently facing a big issue, I have been wanting to run and use Ubuntu on my PC (ProDesk 600 G1 TWR), so I flashed the OS to a USB, and went to boot men-
Yeah so that's where the problem makes itself apparent.
The BIOS.... isn't showing.

And no, the PC works just fine.The HP logo doesn't show, and so does the Windows 10 boot screen! The monitor ONLY receives signal when Windows boots up (Lock Screen). I've heard from multiple people that this ISN'T a display issue, but it clearly is. Proof? Well there are two small lights on the PC case, one green in the shape of the ''I/O for power'' logo on the power button (to show the PC is on), and one white a bit below the green one. The white one blinks constantly when in normal use and boot-up, but spamming the F10 key for BIOS or the F9 key for boot menu, it completely stops blinking and shuts off, indicating that something has actually happened, yet the monitor's still not getting signal.
This means the PC and the BIOS and boot screen and all that, actually work, but the monitor can't show it for some reason.
But there's a chance it's not the monitor (or the VGA cable that it uses) to blame. I have a suspicion it's something to do with the graphics card that's inside the case (Geforce GTX 730), but I can't tell.
So, that's what I'm here for, why the BIOS wont show, and how to fix it. Thanks for hearing me out, any help is appreciated here.

[TheOldMan]

While that seems odd, for sure.  If you try this, does it show the popup menu?

Start tapping the Esc key BEFORE starting the PC and then press the start button.
Keep tapping the Esc key until a popup menu shows. Then pick F9 to show the boot menu.

The F9 option is to change the boot order or select the boot device. You still have to choose the item to make it be first in line, if the one you want is not first.  That will give you the boot to the USB to install Linux.

[AdamJames12]

I haven't tried it yet, but I'm not sure if it'll work, as the entirety of the BIOS and anything related to it isn't showing (even the windows boot screen which is somehow related)

I'll check it out and report my findings to you.

[AdamJames12]

Oopsie, forgot about this post for a while, The ESC key pressing before and after the PC was started sadly didn't help, it indicates that it did something, it just doesn't show it (no signal).

[TheOldMan]

If the graphics card is at fault, as you suspect, then from what I can see, the CPU may have integrated graphics.  The motherboard has VGA and display ports, which would indicate the CPU does have integrated graphics. - That may be CPU dependent.  While you have the case open, check to see which CPU type number is installed, or you may already know the answer.

To investigate that situation, remove the Geforce GTX 730.  Move the monitor lead to the VGA or one of the display ports and try to boot without the graphics card.  If you then get a BIOS or boot screen, at least that situation is revealed.

[AdamJames12]

Yeah the CPU does have integrated graphics, I think.

It's a Intel i5 4th generation (Idk how to check the type number I think that requires removing the cpu cooler which is one hell of a pain)

I'll try removing the gpu and booting the PC, last time I tried it wouldn't budge. 

Some sources also say that it's because it's a VGA cable and I need to use hdmi, I'm not sure of this and my monitor doesn't support it so yeah.

I'll check it out.

[TheOldMan]

According to the specs, it should/could have a i5 4th generation or maybe a i7, which many do have integrated graphics.

You are correct in that the cooler needs to be removed in order to see the numbers on the CPU, so just try to use the integrated graphics for now without checking the numbers.

Just an FYI - the graphics card has a lock at the end of the card slot (opposite end from the plate) That needs to be depressed away from the card to release it.  It looks like a little tail on the motherboard slot body.