I know questions similar to this one, such as this or this, have been asked and solved. However, I tried their answers and none of them worked.
As one of the askers of the questions did, I also tried KDE just out of curiosity, but later, I realized I had plenty with Unity, so I uninstalled it. The only thing that is left to bring my machine to normal is the splash screen.
When I installed KDE, the original Ubuntu's splash screen:
mutated to an ugly screen where I could read "Kubuntu 14.04" with red little pixels.
I have been able to remove that screen following the answers of the questions I linked above. But as a result, I have no splash screen, it goes black with a _ blinking in the upper left corner until the login screen appears.
As I said before, I have already tried the solutions of these other answers, including
sudo update-alternatives --config default.plymouth
which let's me choose between 2 options (one of them apparently duplicated): 
, but none works. Also
$ sudo gedit /etc/initramfs-tools/conf.d/splash
FRAMEBUFFER=y
$ sudo update-initramfs -u
does not work either.
The reason why they don't work might be that, before I found these solutions, I removed with rm all files in the plymouth folder whose names started by kubuntu (kubuntu*). Also, I replaced the content of /lib/plymouth/themes/default.plymout to exactly match:
[Plymouth Theme]
Name=Ubuntu Logo
Description=A theme that features a blank background with a logo.
ModuleName=script
[script]
ImageDir=/lib/plymouth/themes/ubuntu-logo
ScriptFile=/lib/plymouth/themes/ubuntu-logo/ubuntu-logo.script
EDIT: This is the output of the sudo apt-get install --reinstall plymouth-theme-ubuntu-logo command:
$ sudo apt-get install --reinstall plymouth-theme-ubuntu-logo
[sudo] password for antortjim:
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 3 not upgraded.
Need to get 0 B/21.2 kB of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 518027 files and directories currently installed.)
Preparing to unpack .../plymouth-theme-ubuntu-logo_0.8.8-0ubuntu17.1_amd64.deb ...
Unpacking plymouth-theme-ubuntu-logo (0.8.8-0ubuntu17.1) over (0.8.8-0ubuntu17.1) ...
Setting up plymouth-theme-ubuntu-logo (0.8.8-0ubuntu17.1) ...
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools (0.103ubuntu4.2) ...
update-initramfs: Generating /boot/initrd.img-3.13.0-32-generic
I am using Ubuntu 14.04 64 bits. Any ideas? Thank you in advance.
