Gigabyte x470 not detecting ANY gpu... can't post

[Linker]

This has been driving me crazy since yesterday. I temperately unplugged my main gpu for a test (or rather the riser cable from the motherboard as it was vertical mounted for space requirements.), and then my computer suddenly refused to boot! Even when I plugged the riser cable back in it still didn't work.

When I boot, The troubleshooting light gets stuck on VGA, and it starts a beep code I haven't been able to find online. (2 beeps, a pause, and then 4 beeps. All the same duration)

I did manage to get it to boot once, after plugging a gpu in and out over and over, but on reboot it didn't boot again.

 

I have tried:

Mounting (every) gpu without a riser cable

Checking each individual ram stick in each memory slot

Unplugging all the gpus but one (trying each individually)

Checking each gpu (and a GTX 950 as well, making 4 total cards tested) in every slot.

Unplugging the ssd and hdd

Resetting CMOS... numerous times

 

The error is the same with no gpus plugged in as well. I can only assume the motherboard cannot detect the gpus and won't boot because of it.

Is the motherboard somehow broken?

 

Specs:

Ryzen 7 2700x

G.Skill 2 by 8gb 3200

Gigabyte x470 Aorus Ultra Gaming _{(such a stupid name)}

GTX 1080ti & two R7 250x

Samsung 970 Evo 250gb

Seagate 2tb Drive

750W PSU

 

I am completely out of ideas...

Any help is appreciated.