[Black Screen after Grub]

[Bastou]

Dear all,

I'm very new to the topic of Linux and am seeking help for an issue I got after installing Kubuntu 25.10 Desktop. (sorry I do it by memory, maybe some wording is incorrect)

> PC: DELL Optiplex 7050
> 2 Storage:
- 1 SSD with Windows inside
- 1 HDD with nothing inside (TOSHIBA MQ01ACF050, 500Go).
- iiyama monitor, plugged by DisplayPort in the GC.

I did what I thought was the simplest : basic install, choose my empty disc
The install went well, with a "Success" window at the end and i now have the Grub menu displayed at launch.



The Issue :
Grub Menu > Selection of Kubuntu GNU/Linux, (first row)

I have a boot screen with : DELL
Kubuntu

Load few (5-7) seconds, then black screen, back to DELL Kubuntu (4-5 secs), black screen, DELL Kubuntu (even less secs) , black screen and finally my monitor says "No input".

> The monitor worked perfectly for the install and still works for Windows
> Launching windows in the Grub does work well.

what I tried :
> Deactivate Secure boot : no change
> Went inside "Advance Options for Kubuntu GNU/Linux :
All the checks seems "OK",
Then I press "Resume".

And after that Linux does launch but "seems" rather slow (I have no point of comparison but, it seems slow for a brand new OS and empty disc) with a long loading screen with "Plasma by KDE" and a gear icon.

Inside Linux, everything seems up to date.


If you have any insight, I would be happy to get your opinion,
Thanks in advance from a newbie.

[skyfishgoo]

what sort of graphics are you using with that machine? is there a dedicated GPU or and integrated GPU from the CPU

both should really work out of the box unless you checked the [x] install proprietary drivers box during the install.

[Bastou]

Thanks for your answer,

There is both :
the integrated GPU from CPU Intel(R) HD Graphics 630
the GPU: AMD Radeon R5 430


During install, I choose : Normal installation and check the box of "Download and install updated following insallation"

[Bastou]

Anyone has any idea?

[jlittle]

I would try again, as a relatively quick expedient. Especially if the install was done with secure boot enabled.

You may find out more about what is going wrong if at the grub menu on the linux option, you type e then move the cursor to the "linux" line and delete the words "quiet splash", then press f10 to run the item. This may show more of what is going on.

[oshunluvr]

This sounds exactly like a graphics driver issue,

You need to know which video card is active.
Start by powering up and getting to the black desktop screen again. Then press Ctrl-Alt-F3 which should open a terminal screen. Log in and run "sudo dmesg | less" and review the oupput to see if there are any hints about which video is active and and errors relating to it.

You might see a message like "blah blah video device is active", Then you can trouble shoot that device.

Also "xrandr" might have some output