Ubuntu Guide shows you how to fix the "Signal out of range" error after Ubuntu 11.04 is installed
Ubuntu 11.04 final has released and I just installed it from Windows 7 and previous Ubuntu 10.10 was erased. After installation, monitor displayed “signal out of range” while starting up, but I can choose Ubuntu or Windows 7 using up/down arrow keys and press enter to boot up although I can’t even see the grub menu. After grub, it boot into the system I selected and monitor worked again.Signal out of range problem after Ubuntu 11.04 Natty Installed
In other words, while my computer starting to grub the monitor displayed “signal out of range” and I can’t see anything else, then it works again when Ubuntu/Windows splash screen. In addition, at first login I got a message informing that I do not have the required hardware for unity, and that I should choose “ubuntu classic” and it finally logged into ubuntu classic desktop.