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.

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.

After many tests and reboots, I finally got the problems fixed by:

1.) About “do not have the required hardware for unity, and that I should choose “ubuntu classic”" problem, just properly install the graphics driver and unity should start at next login.

Go to System -> Administartion -> Additional Drivers, enable and install driver. At next login/reboot, it login to unity desktop.

2.) About “signal out of range” problem, I think it’s related to the refresh rate or resolution being out of range of the monitor.

And I have tested several methods include editing “/etc/default/grub” and “/boot/grub/grub.cfg”, sudo dpkg-reconfigure xserver-xorg, but they all didn’t work for me.

Finally, I installed a small GUI tool called StartUp-Manger and fixed the problem by changing the grub resolution.

sudo apt-get install startupmanager

UPDATE: SINCE UBUNTU 12.04, startup-manager HAS BEEN DROPPED. USE grub-customizer INSTEAD. SEE THIS POST

BTW: If you get “signal out of range” all through the boot, see nothing even hear Ubuntu booting up. Try following words by prshah on ubuntuforums.org

Try pressing Ctrl-Alt-Numpad- and/or Ctrl+Alt+Numpad+ repeatedly; this will keep changing resolutions in an attempt to find one that works. You will have to wait about 2-3 seconds between each press. If you find a resolution that works, post back on how to make it permanent and/or how to get a suitable refresh rate at which ever resolution you like