Display does not work

[mrjhahn]

Hey it is me again...

So I have installed OSX Lion and it worked for a moment.

Then I downloaded Mountain Lion from the Mac App Store and tried to update the system because my GTX 650Ti doesn't work with Lion..
So I put the USB in the new PC but the display from the Mainboard doesn't work anymore.

I unplugged the Graphic Card but nothing happend. The Mainboard doesn't Respons. Just the 650Ti does but I can't go into any settings in Lion because of the Graphic Card...

The Maindboard worked today...

Do you have any solution for me?
It would be great!

Sorry for my terrible englisch.

 

[Going Bald]

Can't help without hardware list.
Please follow forum rules and put your mainboard, cpu and gfx card at least in your profile.