I had ever got “No Input Signal” displayed on screen after boot up from fresh Ubuntu installation, but it was certain that system started and booted into blank screen because the log-in sound would play. Until I read the thread on ubuntuforms.org I didn’t search and solve the problem because I was just testing my new created Live CD on my friend’s machine and he was not going to use Ubuntu.

Problem 1: While using the live CD to install Ubuntu the monitor display a “No Input Signal” after selected either install ubuntu or install ubuntu without any changes to your computer.

Solution: The nomodeset option should work on the live CD

Problem 2: After installation, while starting Ubuntu from local disk the monitor displays the “No Input Signal” and then it boots into blank screen without Grub menu show.

Solution: Press and hold down Shift key from Bios screen until see the Grub menu. Highlight the first entry, press “e” to edit it. Navigate to words “quiet splash”, delete them and type “nomodeset” in their place (without quotes). Press Ctrl + X to continue boot.
Once on the desktop, go to System > Administration > Additional Drivers and activate the recommended drivers and the problem should go away for ever.

Check here