So I removed the gtx 960 and also the ssd with windows 7 installed.
I installed the original gt120 arrived yesterday x mac pro 3.1, connected the gt120 cable to the monitor and put a blank ssd, inserted the original installation dvd 1 mac pro 3.1 and started the mac pro.
Nothing to do black screen and nothing can be seen, the DVD can be heard spinning for a few minutes and then stops, I also tried to change the DVD player instead of the integrated one on the mac pro I connected an external one, nothing changes.
After restarting with DVD inserted I clicked ALT then I tried with C and then I tried to restart without clicking anything but always black screen, then either the gt120 does not work or it is not his or what else could it be ???
I'm going crazy!
thanks.