Why is there no signal to the video card?

Question

Iron

I assembled a PC, connected the VGA monitor to the video card first, there were 5 beeps, which, according to the documentation, means "lack of a vga cable". Connected to the built-in graphics, everything worked. So by default, the BIOS is built-in. I went into BIOS, found the default graphics item and made pci express, saved the settings and plugged vga to the video card. I try to turn it on - it does not work. Again 5 peeps. The video card itself is determined in the system, it is working. But for some reason there is no signal from it to vga. Then I tried again to include the cable in the integrated graphics - but there is nothing here, because it is disabled in the BIOS. Now two video cards show a black screen. I had to reset the BIOS and return the default settings again so that at least the built-in one worked.
What can be wrong? There is no multi-monitor item in the BIOS, on the advice of Google.
Motherboard asrock, UEFI Bios.

Answer 1

So, about "multi-monitor" I understood this "Поддержка трех мониторов", that is, all three outputs of the motherboard itself (video core) work together.
And here's the "weirdness"

Разъемы
- 1 x PCI Express 2.0 x16 (PCIE2: в режиме x1)

That is, it is very similar that this is a stupid full-size connector, but there is only "1 line" in it. In theory, this is quite enough for not "top-end graphics", but ... this is where "nuances are possible". Well, finally, it’s written in English and white in the manual in the same place (you didn’t have a booklet
in the box with the motherboard ? -And you didn’t read it? - on page 17 :) - correction, there is no complete manual in the kit, only on the disk: ( ):

Warning:
To ensure better graphics compability, the BIOS is set to "boot from Onboard VGA"
as default even the user install a VGA card on PCIe slot.