Hi,

I have problem with Ubuntu upgrade. I have laptop with intel GMA 4500m video card and Ubuntu OS, but when i have upgraded ubuntu to 11.04 version i received a big problem, computer screen become dark, and i can't see anything... but when i plug monitor via VGA port, i cant see everything, so i have googled and found that there is some incompability with GMA 4500m video card and ubuntu 11.04. Maybe someone knows how to fix that problem? should i change something in my xorg files ?

I googled that, and, unbelievably, found that this bug was known since the beta version of 11.04 and is still not fixed yet. And that for a very common piece of hardware. This only confirms my view on Ubuntu's quality.

But anyways, to your problem: The problem is that the backlight of the display is not working. There seem to be different solutions for different laptops:
1. Try to adjust the brightness of the screen with the appropriate keys for your laptop. This is somewhat the simplest solution, if it works.
2. Attach a monitor and try this command in a terminal:If it works you should at that command to your rc.local file.