Displays overlapping on Kubuntu 20.04 on Asus ZenBook with Nvidia GPU

The problem ScreenXpert overlaps the main screen when Nvidia MX250 is chosen as main graphics card. The same thing doesn't happen with Intel graphics as primary card.

The solution is to disable the ScreenXpert monitor before the welcome screen loads.

The first step will be to find the name of the ScreenXpert monitor. In order to do it, run the following command:

xrandr --query

In the output find the monitor with only two resolutions:

HDMI-2 connected (normal left inverted right x axis y axis)
1080x2160 50.03 +
504x1000 50.03

HDMI-2 is what we are looking for.

After having found the monitor name we need to edit the file
/usr/share/sddm/scripts/Xsetup
and add the following line at its end:

xrandr --output HDMI-2 --off

Source: https://www.reddit.com/r/kde/comments/755q9a/sddm_and_triple_monitors.

Running Zenmap on Ubuntu 20.04

1. Download Zenmap packages and convert rpm packages to deb as described here.
2. Install python 2.x by running
   
   sudo apt-get install python
   
   If you try to run Zenmap now, you'll get the following error:
   
   Could not import the zenmapGUI.App module: 'No module named gtk'
   
3. Download the following packages from Debian repositories:
   • https://packages.debian.org/buster/python-gtk2
   • https://packages.debian.org/buster/amd64/python-cairo
   • https://packages.debian.org/buster/amd64/python-gobject-2
4. Install python-gobject-2, then python-cairo and then python-gtk2.
   
   You may need to fix dependency problems by running
   
   sudo apt --fix-broken install.
   
   
5. Enjoy Zenmap!

Fixing Dell Inspiron 3162 PgUp/PgDn/Home/End keys issue in Ubuntu

1. Create file /etc/udev/hwdb.d/95-custom-keyboard.hwdb
2. File contents must be
   
   # Dell Inspiron 3162
evdev:atkbd:dmi:bvn*:bvr*:bd*:svnDell*:pnInspiron*3162:pvr*
 KEYBOARD_KEY_c7=!home
 KEYBOARD_KEY_cf=!end
 KEYBOARD_KEY_c9=!pageup
 KEYBOARD_KEY_d1=!pagedown
   

Important! There must be a space before KEYBOARD_KEY keyword.
 
3. After editing the file, run the hwdb re-index:
   
   sudo udevadm hwdb --update && sudo sudo udevadm trigger

Source: http://wiki.archlinux.org/index.php/Dell_Inspiron_11_3000_(3162)

Ubuntu 19.xx/20.xx hangs on splash screen during boot

The solution is to disable the splash screen during boot.

1. Open /etc/default/grub file in editor as superuser.
2. Find the following line:
   
   GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
 
3. Change quiet splash to quiet or nosplash.
4. Save the file and run the following command:
   
   sudo update-grub2

Source: How do I disable the boot splash screen, and only show kernel and boot text instead?