After upgrading to Yosemite, I see just noise on the external monitor, using a MDP to HDMI converter and an HDMI to DVI cable. It worked very well on Mavericks. I have no display now after updating, it just shows grey noise. Tried resetting SMC & PRAM. Additionally, I have tested each of the cables individually and they are okay, so it has to be a software problem.
It shows flickers in red color sometimes.
Macbook gives display on another setup, but flickers a lot. (my friend's) its a MDP to VGA adapter plugged to VGA monitor.
Mine gives no display, I'm disappointed. Need help please.