This is a weird one that's had me banging my head into the wall for a day.
At BIOS, Input works fine. Keyboard works to get into setup, mouse works when inside setup.
I have two HDDs. one running Windows, the other Ubuntu.
On the Ubuntu install, keyboard works fine in GRUB.
However, once the respective OS's start booting, All input is lost. If a phone was connected, it stops charging. When the OS is up, the input is still lost. Even though the lights are flashing on the Ethernet adapter, there's no network connection at all. The same for Ubuntu.
I can't use the OS's, even if I had no mouse but had a keyboard I'd be able to, but nothing, not even using PS/2 devices works.
Is this a known fault / is there a default BIOS setting that causes this?
I've tried enabling VT-d, removing motherboard battery, but neither seemed to work. Tried draining power too, that didn't work. Anyone know how to fix this?