This one is quick and simple; it compiles a bunch of information I saw floating around Reddit etc. combined with my own experience.

So I upgraded my PC and converted the old parts into a server, replacing my various abominations with something simple, reliable, and enormously overpowered. (And yet another increase on the electricity bill. :/)

The CPU is a Ryzen 9 3950X, and the motherboard is an X570 Aorus Master. Just one problem– after I built the server, put my Unraid drives in it, and made sure it booted up, I removed the GPU, moved it into the corner, and discovered that it wouldn’t POST after I moved it.

What gives? Well, apparently, these motherboards absolutely insist that they must have a working GPU, with a working display, attached before it will proceed with powering on. Which is insane, but, well, there’s a workaround.

Here’s what you have to do:

• Have a GPU and monitor attached. Enter the BIOS.
• Under “Settings -> IO”, Set “Initial Display Output” to “PCIe 3 Slot”
• Under “Settings -> Boot”, Set:
  • Fast Boot -> Enabled
  • VGA Support -> Auto
  • CSM Support -> Disabled

Save settings, shut down, and remove the GPU. For the next boot only, the “VGA” light on the motherboard, indicating a problem that blocks boot, will still light up, but boot will proceed as normal.

If you reboot again, you’ll have to re-attach a GPU, re-enter the BIOS, shut down again, and re-remove it before it’ll POST headless.

Why? I have no idea. But this is, frankly, a plus for me, as it further discourages me from touching the device that I need to be reliable, always-on, and not tinkered with, or at least tinkered with as little as possible. Such a high barrier to rebooting means that I’m unlikely to do it.

Anyway. Hope this helps someone.