[lubuntu] Black screen with check disk result and no graphic interface after install

Hello,

I just installed Lubuntu 16.04 LTS on an old Dell desktop unit.

I have no trouble to start the install from my live USB but after installing, I get the result of mounting the main disk, but no graphical interface.

Swithching to different TTY shows me the login prompt but revert to this strange message automatically. It's like X is not starting or displaying correctly or I have other trouble.

Do you have a suggestion on how to solve this?

Kind regards.