Plymouth or Plasma Boot Screen is not loading new themes, nor the preview images, the settings seem to load but do not take effect.
Also the images always remain empty without preview images. I will show images below, more information about my team in my profile.
Just for your information, just because that theme is called “Plymouth” doesn’t mean that it has anything to do with plymouth itself.
plymouth is a layer that covers the terminal output with a graphic during the system’s boot sequence. That which you have highlighted in your screenshot is a Plasma splash screen, which only becomes active after logging into Plasma.
When looking for troubleshooting advice, it is important to correctly represent the facts, or else people would be starting off on the wrong foot. I have therefore edited your thread title to more correctly reflect the problem.
As for the problem itself, all I can advise you to do is to log out of Plasma completely — you have to be looking at the login screen again — and to then switch to a tty, log in as yourself, and issue the command… 
rm -rf ./cache/*
Then, exit the command-line session by hitting Ctrl+D, switch back to the GUI login screen, and log in again. Hopefully this will remedy the problem. If it doesn’t, then I’m afraid I’m going to have to leave it to someone else to offer advice. 
What about the things?
pacman -Qs plymouth
grep plymouth /etc/mkinitcpio.conf
ls /usr/share/plymouth/themes
OP’s problem is not with plymouth — and I rest my case on what I wrote in reply to the OP — but with a Plasma splash screen that somehow confusingly was named “plymouth theme”.
Ooh thanks for information, It is good to clarify those terms in a friendly way.
I will test the session although I have already tried it and it has no modifications, it is from this new recent installation in the system, I had reinstalled Manjaro because I changed disk
I was at first confused as to why they included both.
And it may be a simple confusion.
But … by either reading the spanish or by comparing to a non-plymouth kcm screen (And maybe noting the lack of ‘none’ option) … you will see it is the plymouth kcm … not the ‘splash’ kcm.
I will try the Aragon tests and immediately if there is none I will see these
In that case, my mistake. No hablo Español, lo siento. 
It doesn’t hurt to ask at least jsjsjs
The one above is ‘pantalla’ de bienvenida (‘welcome’)
The highlighted example is ‘arranque’ (‘boot’).
So its not a perfect match anyways … it would be nicer for all involved to just use the name ‘plymouth’ 
I have amended the thread title again accordingly. 
pacman -Qs plymouth ✔
local/plymouth 22.02.122-16.2
A graphical boot splash screen with kernel mode-setting support
local/plymouth-kcm 5.27.10-1 (plasma)
KCM to manage the Plymouth (Boot) theme
local/plymouth-theme-manjaro 2.2-1
Plymouth theme for Manjaro
HOOKS=(base udev autodetect kms modconf block keyboard keymap consolefont plymouth filesystems fsck)
s /usr/share/plymouth/themes ✔
bgrt fade-in manjaro script spinfinity text
details glow plymouth-theme solar spinner tribar
Looks like you have what you should.
Next questions might be … is initram and grub updated/installed?
Oh and splash should be in the boot options too:
grep splash /etc/default/grub
I might use the latest install-grub script to update the bootloader (install first, along with update);
sudo pacman -Syu install-grub
sudo install-grub
And regular old rebuild initram and update-grub;
sudo mkinitcpio -P
sudo update-grub
Ok, so what we are doing is how to reset the correct init installations?
pamac install install-grub 1 ✘
Preparando...
Sincronización de bases de datos de paquetes...
Resolviendo dependencias...
comprobando conflictos internos...
Para instalar (1):
install-grub 2.12-3.10 core 23,2 kB
Tamaño total de descarga: 23,2 kB
Tamaño total instalado: 6,9 kB
Aplicar transacción ? [s/N] s
==== AUTHENTICATING FOR org.manjaro.pamac.commit ====
Se requiere autenticación para instalar, actualizar o eliminar paquetes
Authenticating as: Jose Alberto Zerpa (roobertjack)
Password:
==== AUTHENTICATION COMPLETE ====
Descarga de install-grub (2.12-3.10) iniciada
Descarga de install-grub (2.12-3.10) finalizada
Comprobando llavero... [1/1]
Comprobando integridad... [1/1]
Cargando archivos de los paquetes... [1/1]
Comprobando conflictos entre archivos... [1/1]
Comprobando espacio disponible en disco... [1/1]
Instalando install-grub (2.12-3.10)... [1/1]
Ejecutando hooks de post-transacción...
Arming ConditionNeedsUpdate... [1/2]
Refreshing PackageKit... [2/2]
Transacción terminada con éxito.
sudo mkinitcpio -P ✔ 11s
[sudo] contraseña para roobertjack:
==> Building image from preset: /etc/mkinitcpio.d/linux66.preset: 'default'
==> Using default configuration file: '/etc/mkinitcpio.conf'
-> -k /boot/vmlinuz-6.6-x86_64 -g /boot/initramfs-6.6-x86_64.img --microcode /boot/intel-ucode.img
==> Starting build: '6.6.10-1-MANJARO'
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [autodetect]
-> Running build hook: [kms]
-> Running build hook: [modconf]
-> Running build hook: [block]
==> WARNING: Possibly missing firmware for module: 'xhci_pci'
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
-> Running build hook: [plymouth]
-> Running build hook: [filesystems]
-> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: '/boot/initramfs-6.6-x86_64.img'
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux66.preset: 'fallback'
==> Using default configuration file: '/etc/mkinitcpio.conf'
-> -k /boot/vmlinuz-6.6-x86_64 -g /boot/initramfs-6.6-x86_64-fallback.img -S autodetect --microcode /boot/intel-ucode.img
==> Starting build: '6.6.10-1-MANJARO'
-> Running build hook: [base]
-> Running build hook: [udev]
-> Running build hook: [kms]
==> WARNING: Possibly missing firmware for module: 'ast'
-> Running build hook: [modconf]
-> Running build hook: [block]
==> WARNING: Possibly missing firmware for module: 'wd719x'
==> WARNING: Possibly missing firmware for module: 'qed'
==> WARNING: Possibly missing firmware for module: 'qla1280'
==> WARNING: Possibly missing firmware for module: 'aic94xx'
==> WARNING: Possibly missing firmware for module: 'bfa'
==> WARNING: Possibly missing firmware for module: 'qla2xxx'
==> WARNING: Possibly missing firmware for module: 'xhci_pci'
-> Running build hook: [keyboard]
-> Running build hook: [keymap]
-> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
-> Running build hook: [plymouth]
-> Running build hook: [filesystems]
-> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: '/boot/initramfs-6.6-x86_64-fallback.img'
==> Image generation successful
sudo update-grub ✔ 37s
Generando un fichero de configuración de grub...
Encontrado tema: /usr/share/grub/themes/manjaro/theme.txt
Encontrada imagen de linux: /boot/vmlinuz-6.6-x86_64
Encontrada imagen de memoria inicial: /boot/intel-ucode.img /boot/initramfs-6.6-x86_64.img
Found initrd fallback image: /boot/initramfs-6.6-x86_64-fallback.img
Aviso: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings ...
Root filesystem isn't btrfs
If you think an error has occurred, please file a bug report at "https://github.com/Antynea/grub-btrfs"
Found memtest86+ image: /boot/memtest86+/memtest.bin
/usr/bin/grub-probe: aviso: tipo de dispositivo nvme0n1 desconocido.
Found memtest86+ EFI image: /boot/memtest86+/memtest.efi
/usr/bin/grub-probe: aviso: tipo de dispositivo nvme0n1 desconocido.
hecho
Pst: I currently speak Spanish, but I need to learn more English, which is why I open these forums in English since it helps me practice more.
I only stopped by to offer this tip:
To have your command output in English (which would probably help most reading it), prefix any command with LC_ALL=C; for example:
LC_ALL=C pacman -Si plymouth
Also, if you ever want to completely uninstall Plymouth, the correct procedure can be found in the Manjaro Wiki Plymouth article, under the heading of REMOVAL.
That is all. Cheers.
This problem is a long-standing, neglected bug in ‘plymouth-kcm’.
Only on Ubuntu does it work.
To make the settings take effect, you need to update Grub yourself after selecting a theme in the GUI.
sudo mkinitcpio -P
sudo update-grub
Alternatively,
sudo plymouth-set-default-theme -R {theme}
As it seems from KDE Plasma and its forum, it really is, I have already sent it and reported it to the Plasma team, it may be resolved in a future update.
Thank you very much, in part what you have shown me is to regenerate the init, update the grub, and place a theme manually from the terminal, correct?
Thank you very much, in part what you have shown me is to regenerate the init, update the grub, and place a theme manually from the terminal, correct?
I am sorry.
I didn’t know that it was fixed for Arch(mkinitcpio).
However, it will not work correctly if the update-alternatives command is enabled.
I thought update-alternatives was only for Debian, but it exists on my PC.
I don’t know where it came from.
In the virtual, up-to-date and clean ManjaroKDE environment, update-alternatives was not included, so the mkinitcpio -P command was executed when saving.
The functions of plymouth-kcm end here.
update-alternatives (with an ‘s’)
is provided by the dpkg package.
(why you have that I dont know.)