While I call it init, many will assume I am referring to the boot init, but I am actually referring to the bios initialization (init).
That said, most BIOS inits go in this order:
Power Detection check. If enough power, proceed.
CPU program link, CPU calls the BIOS to basically wake up and run the bios program.
Ram Detection check. If RAM is present, the BIOS will use about 64k to load from ROM to RAM (called the bios reserve area) that then does the next steps.
Hardware Detection check. Identifiers of the hardware are detected, enumerated, configured and initialized.
Boot Sequence is initialized whereby the BIOS does a handoff to the bootloader.
It’s during the hardware detection phase when the display is initialized by the gpu and you often see it displaying the bios version, then counting RAM. If the gpu is working BUT the display out isn’t, it’ll actually continue to boot 100% of the time (it doesn’t care). If the gpu hardware itself doesn’t respond correctly to the BIOS request however, it sends the hardware detection of the BIOS into a loop or shuts the system down, never getting to the final step: boot sequence.
Depending on the bios type, it may or may not show numlock. I’ve also seen it act differently on UEFI enabled systems than when it’s set to classic bios. So, it just depends.
Regardless, see if you can source another pcie gpu for testing this. It only takes a minute and tbh, it doesn’t hurt to have a cheap used pcie vid card in your pc tools for such things.