How to recover splash screen

Open the terminal and type:

sudo update-alternatives --config default.plymouth

Select the original default and then

sudo update-initramfs -u

Reboot.

If it still doesn't appear then open a terminal and type the following command:

sudo -H gedit /etc/initramfs-tools/conf.d/splash

or this command by Alt+F2

gksu gedit /etc/initramfs-tools/conf.d/splash

This file may not exist, so you may be creating it from scratch now. Enter the following content on the file you opened on the previous step:

FRAMEBUFFER=y

Close and save the file. Now, run the following command to commit the change:

sudo update-initramfs -u

Reboot and enjoy your Plymouth splash screen.

I know this is an old post, but for others who need help, here's another way, which worked for me in Ubuntu 12.04 (after I got stuck with the Lubuntu splash):

1) Open a terminal and type gksu gedit

2) Enter your password and press enter

3) Click "File" --> "Open"

4) Click on "File System" and go to /lib/plymouth/themes. Open the file "default.plymouth"

5) Make it so that the file says this:

[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

6) Save the file and exit.

All done!