I had a USB keyboard connected through a KVM switch (keyboard, video, mouse) to an Ubuntu Server. Then I had to remove the KVM and then I've connected a PS/2 keyboard to the server. Now I can't type into the terminal. But I still can switch TTY by pressing Ctrl + Alt + F2 (or F3, F4) but the login screen does not appear there only a blinking cursor. I can also return to TTY 1 (Ctrl + Alt + F1).
That's what the terminal shows:
I can SSH into the server no problem. The question is how can I make the keyboard work without restarting the server?