I upgraded my system from 11.10 to 12.04. After pressing the Power On button, I don't get the Ubuntu boot screen with the dots. All I get to see is a full black screen until the login screen is displayed. I have a Lenovo T420. I have also enabled the LUKS encryption and currently, I type the LUKS passphrase on a full black screen which is accepted and the system continues to boot. Is this a known issue on ubuntu 12.04 ? Is there a known fix for this issue ?
I had the same problem when I installed.But soon I realized that this was caused due to graphics driver.After then I installed the required graphics driver and things came back to track.
Try one of them by setting in your grub.cfg I am not sure which one was the right one.
Only try those which are inside two asterisks ,and dont copy whole line, otherwise result could be weird.