I have a Dell Precision Tower 5810, and I was trying to install Ubuntu 18.04 on it. I created a bootable usb with Roofus 3.1 in Windows 10 (as described here).
Then tried to follow Dell's guide here, but I could not find the file SHIMx64.EFI...
Still I made sure the Secure Boot was enabled, the Legacy Option ROMs was not enabled, and the Boot Option was set to UEFI, pushed my usb stick to the top in the Boot Sequence, and exited.
It booted with no problem to my usb stick, showing the options "Try Ubuntu", "Install Ubuntu", etc. But whichever option I used, led me to a blank screen...
Eventually, thanks to this, I added the nomodeset option and I could access the "Try Ubuntu" option... I installed Ubuntu and the installation went through with no problem at all.
Now Ubuntu boots, but the instant the login screen shows up, the screen goes blank (without even letting me type my credentials). I tried pressing the Right Shift key like specified here, but to no avail. I checked all the "Similar Questions" suggested, but none of them work.
Note that the first time I booted after the fresh install, I saw a "Perform MOK management" screen with the following options, but I just selected "Continue to boot".
Any clue anyone? I really need this computer working (with Ubuntu 18.04 if possible) asap! Many many thanks.