Fedora 40 won't boot anymore???

Hello,

We should start by specifying when the black screen occurs. Indeed, the Linux startup happens in several stages:

1. Choosing the system to boot (grub)
2. Starting services (notably the login manager)
3. Displaying the login manager (graphical interface where you enter your login and password and choose your graphical environment)
4. Launching the graphical environment (gnome, KDE, cinnamon, etc...)

Depending on when the bug occurs, we can more easily identify the culprit.

If it's just before 3

It is likely that the video card driver is either not installed or improperly installed. In this case, the graphical server (also called server X), typically Xorg or Wayland, crashes and in practice, you see a black screen.

This is often the case when the computer was previously using a proprietary driver (let's say NVIDIA) and the kernel has been updated in the meantime. If this hypothesis is correct, in GRUB (the menu that appears at startup), in the advanced options, you can choose to boot on an earlier kernel. The idea is to boot using the earlier kernel for which the driver in question is still installed. If you manage to boot on an older kernel, we have found the cause.

If no kernel works, bad news, the problem is likely more serious, but well, it's an opportunity to learn. To proceed with a repair, you need to type the appropriate commands in text mode (console). Normally, you will then be prompted to enter your login; you are in the right place. You need to type your login, enter, then your password in silence, then enter. You should then see a command prompt of the form login@machine:~$. If you have reached this point, congratulations, you have launched a shell (a command prompt) from which we can hope to repair and recover information.

1) Retrieve the model of the video card (or video cards): type the following command in your terminal (then enter) and report the result.

 lspci | egrep "3D|VGA" 

Example: Here, we see that this PC has an Nvidia card and an Intel card

(mando@velvet) (~) $ lspci | egrep "3D|VGA" 00:02.0 VGA compatible controller: Intel Corporation UHD Graphics 620 (rev 07) 00:13.0 Non-VGA unclassified device: Intel Corporation Sunrise Point-LP Integrated Sensor Hub (rev 21) 01:00.0 3D controller: NVIDIA Corporation GP108M [GeForce MX150] (rev a1)

2) Report to us the list of installed xorg packages with the following command:

dnf --installed list | grep xorg | grep video

We need to ensure that the package(s) corresponding to your video card(s) is/are installed. Normally, this should be the case since you just migrated to a more recent version of Fedora.

3) Report to us any errors from the graphical server:

grep EE /var/log/Xorg.0.log

Typically, if a driver is improperly installed, we should see an error here.

If it's just between 3 and 4

If the login manager appears but the graphical environment does not, it’s likely that the graphical environment itself is broken. This could be due to a faulty update, an outdated configuration profile, etc...

As this explanation is less likely, I will not elaborate on it for now. If you think you are in this case:

• confirm with us that you were not using automatic login (i.e., you had to enter your login and password to start a graphical session when Linux booted);
• let us know which graphical environment you are using (gnome, KDE, cinnamon, XFCE, ...)

If you are considering reinstalling Linux

Not being a big fan of RPM, I can only encourage you to take advantage of this misadventure to install a Linux distribution based on APT. Among mainstream distributions, I encourage you to consider:

• Linux Mint (Cinnamon or Mint variant);
• or any variant of Ubuntu.

Whatever distribution you choose (including if you want to install Fedora 42), the installation procedure is generally always the same:

1. If you have important documents, it's best to save them beforehand, for example on a USB drive.
2. Download an installation ISO.
3. Prepare an installation disk (USB, DVD...) with this ISO file using a tool like Rufus.
4. Restart your PC from this disk (this may require you to adjust the boot sequence in your BIOS or press a key, indicated on the screen, allowing you to choose which disk to boot from).
5. Start the installation: in your case, you should reuse the existing partitions (swap, /, and /home) using manual partitioning. In theory, the size and file system used for each partition allows you to know which one it is (typically swap is in swap, few GiB, / is in ext4 and is a few tens of GiB, and /home is in ext4 and is often significantly larger than /). In your case, you need to re-declare each partition, making sure to format swap, /, but not /home (otherwise the documents residing there will be destroyed).

Good luck