MP 1,1-5,1 mac pro 2009 5.1 firmware - black screen with 5770 video card

[smf88011]

I am having difficulty with no video coming up on my 5770 video card with my 2009 Mac Pro 2009 with 5.1 firmware. I just get a black screen. The GeForce 120 boots fine. Power is plugged into the card, it is an "Apple" version of the 5770. It is connected to my monitor via DVI cable - the only port on my card if memory serves.

Can you give me a list of things to check to see what is going on with this card? I also get black screen with a GeForce 970 that worked in my previous 2009 Mac Pro with 4.2.

 

[Macschrauber]

Try a deep nvram reset. Hold cmd-opt-p-r altogether until the Mac chimes 3 times.

4.1 crossflashes tend to have botched nvram streams in their firmware.