No keyboard, no network, no audio after reinstall of kubuntu 20.04

Question

I have been using kubuntu since about 2008 I think, but now something really weird has happened.

This summer I upgraded my old installation of kubuntu 16.04 to 20.04. No problem, everything worked perfect! I think I did it by complete reinstall rather than upgrade, but I'm not completely sure.

Anyway, last week my very old boot drive (SSD) got some error and the system wouldn't boot even after fsck. I bought a new SSD drive, and also a CPU fan since the old was starting to be noisy.

I installed the CPU fan, which required me to remove the motherboard since the connectors were of a different type of what I had before. I'm always a bit nervous when doing that kind of thing, but it seemed to work fine. I installed the drive and installed Kubuntu 20.04 from the same flash memory as I used previously during the summer.

After rebooting the system, Kubuntu started up but I got stuck at the login prompt as the keyboard did not work. After a while I managed to login using a virtual on-screen keyboard, and noticed that the network did not work, and I don't think the audio worked either as it was a disabled symbol over the speaker icon in the system tray (didn't investigate that further).

After some investigation I found out that:

• If I connected yet another keyboard I could use that, but I couldn't get my main keyboard to work regardless of which USB port I used.
• The keyboard and network worked fine during the install, and they also worked if I selected "Try Kubuntu" instead if install. I also tried booting another live CD (Slax) and that also worked fine.

I tried to change various things in the BIOS just in case. I have tried all combinations of UEFI/Legacy and Secure boot Enabled/Disabled, but it is always the exact same problem.

I also tried to burn a new DVD with Kubuntu 20.04.1 and tried multiple times to install from that, but always the same problem.

Finally I tried to install Ubuntu 20.04 instead, and that worked perfectly after the install. No problem with the keyboard, network or audio at all.

As a next step I installed KDE in this ubuntu installation, and got to select between SDDM and GDM (I think?). I selected SDDM. After reboot everything still worked fine, except that when SDDM starts it puts a virtual keyboard all over one of my screens which perhaps indicates that it somehow don't think that I have a HW keyboard attached? But anyway, my HW keyboard still works, so it is not a big deal.

So after lots of trial and error and frustration, I have more or less configured my system as it was before the HW crash.

But does anyone have an idea of what has happened? Anyone have the same problem?

Did I somehow damage my motherboard or something when I installed the CPU fan? I think it is unlikely as my system seem to be stable and work work just fine except when I use kubuntu, right? But something strange is going on...

Some system info: Stationary computer using AMD FX-8320 on a Asus M5A97 R2.0 motherboard.

Answer 1

I just fixed a very similar problem after a Windows-10 update wiped my XUbuntu 20.04 OS and partition. On a desktop, duel booting Windows-10/XUbuntu 20.04 with a Logitech wired USB keyboard. Also, I tried many times to reinstall from an XUbuntu 20.04 boot DVD but it would fail.

There is a solution posted here for the keyboard that worked, I'll try to find the link for it. Apparently, Ubuntu 20.04 mistakenly loads a tablet keyboard driver by mistake. One needs to change a configuration file [somewhere] and then any keyboard will work again.

My DVD boot failure was due to an older DVD recording program (Nero 8 or similar). Fixed that by going to the latest Nero burning software. Even did the cksums but either that Ubuntu 20.04.2 install was bad or it was the DVD burn.

Finally I too installed another motherboard {a Gigabyte, ca. 2011, supporting 16GB Ram} which also had PS2 ports for the keyboard. I believe your MB fan change is extremely unlikely to cause the issues you described. When motherboards/ CPU's fail, pretty much nothing works. Motherboards also seem to have some redundancy in components.

If you're still having problems, reply and I can look for the keyboard config file which needs to be changed.

Answer 2

Here is a solution to the No Keyboard error some Ubuntu 20.04 installs have had. Sorry for my long delay: it took some time to hunt for the correct solution

Ubuntu 20.04 - keyboard not working

This worked perfectly for me (XUbuntu 20.04, desktop, Logitech USB (wired) K740 keyboard).