Bad MB killed my CPU?

Hi guys
I had a old mobo in here that i never tested to see if she was ok or dead like the cpu was in her.
Then i had used my working cpu on the mb and what apon.... well the mobo is dead like i had thought.
Now i go put my cpu in the working mb and what apon... all working but the screen get nothing, but the rotations of the grafic is all time incresin and decreesing and i press the button to shoot down the pc and nothing, still works....
Well did the mobo died or i killed my cpu putting im in a damage mobo that didnt even worked 1 sec.