I just installed ubuntu 20.04 lts. There was no problem during the installation process. But after the reboot and choosing Ubuntu at the grub menu (I also use windows 10), it's just nothing, only black screen. I have tried to edit the command and added "nomodeset" like the others told. But nothing's changed.
My laptop is Lenovo g405s, AMD A8 processor, Amd Radeon graphic card, and using legacy mode
I have updated Ubuntu 19.10 to 20.04 on my laptop Dell Latitude 7490. After reboot I had the same problem.
Machine: Dell Latitude 7490
Dual boot Ubuntu 20.04 + Windows 10 (it was working fine with 19.10)
Bios: Uefi, security OFF.
None of the steps helped
An error occurred during the repair.
Please write on a paper the following URL: https://paste.ubuntu.com/p/sfyBwkyNGV/
In case you still experience boot problem, indicate this URL to: boot.repair@gmail.com
You can now reboot your computer. Please do not forget to make your BIOS boot on sda1/EFI/ubuntu/shimx64.efi file!
If your computer reboots directly into Windows, try to change the boot order in your BIOS. If your BIOS does not allow to change the boot order, change the default boot entry of the Windows bootloader. For example you can boot into Windows, then type the following command in an admin command prompt: bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi
It can be your grub fault , so you can go live on your ubuntu and update-grub , it could fix it , tell me the result
If the above doesn't work try the following:
Make sure that you use the same BIOS as the one you use for windows. If you use UEFI for Windows you have to make sure you pick the option to boot the Ubuntu installer in UEFI mode as well. You might also want to try and install Ubuntu in 'safe mode' as that makes sure that your graphics will work no matter what graphics processor you use (if you use one at all). If neither of those work then I advise you simply reformat your bootable USB and download another copy of the ISO and flash it again and try that. If you used RUFUS it's possible you got something wrong so you should also try a program called Balena Etcher, they do the same thing it's just that Balena Etcher is easier to use as all you do is select the file and it takes it from there.
Keep us updated.
In my case the black screen resulted by some kernel issues. Further I couldn't even start the live-cd - it stucked after loading grub.
I could solve the problem by using the acpi=offoption. As I found out the 2nd function keys (like screen-brighter, ...) didn't work.
Therefore, start your notebook and in the grub menu, type e in order to edit the parameters and add this option to the line starting with "linux". After editing the line should somehow look like
linux /boot/vmlinuz-5.4.x-xx-generic root=xx=xx-xx ro quiet splash $vt_handoff acpi=off
Press F10 and the notebook should boot.
First I googled through the kernel development sides and compiled/installed the 5.7 kernel, which worked fine - no problems anymore.
However, Ubuntu released the kernel 5.4.0-31 (I think it was 18 May 2020), and I switched back to the Ubuntu kernel (which also works). All you have to do is an update sudo apt update and sudo apt upgrade ; this should automatically install the newest kernel. So make sure the 5.4.0-31 kernel is installed (e.g. make a ls /boot ).
