Problems connecting Monitor

So I have been using a Dual Monitor Setup on my macbook and it has had no problems, while since last week.

I started up my macbook like every morning and tada, the external screen was black, I thought thats strange so I unplug the Mini DisplayPort to DVI Adapter and plugged it back in, the macbook screen turned blue for a second like it does when it recognizes a monitor being plugged but still stays black.

I tried different monitors and cables nothing is working!?!

Could it be the Mini DisplayPort to DVI Adapter or maybe I have to reset something?

 

Yes I did but did not help I will try again.

thx for the quick reply

 

Nope still didnt work I guess I have to get a new displayport cable