Mac pro not detecting the screen?

[Caveman.]

Hello, I have been a Mac user for the past 4 years and this is the first time that this issue has popped on my desk.
For the past few months my mac pro (8 cores) hasn't been detecting my apple cinema display. It produces sound but not image. I tired to use the shortcut cmd+f and type detect display but nothing happens.
Can anyone please help?

 

[interslicer]

the detect displays feature is a button in the display preferences in system preferences.

what kind of graphics card do you have? have you tried switching what port on the card its plugged in to?

 

[Caveman.]

Yes I do know that its in the system preferences, i tried that but no luck
I cant really switch to anything because there is no monitor.. I cant see anything.