I have a very strange problem which is affecting my (previously perfect) hackintosh. Ever since i upgraded to macOS Sierra, about 90% of the time when it boots into the login screen my mouse cursor isn't on screen. I'm pretty sure this isn't a usb issue, because my keyboard is still working, and i can plug the mouse into loads of different usb ports and the problem remains. Then, at any point between 1-5 minutes, the screen goes black, and then comes back and my mouse is working! At this point, i can login and use the computer without issue.
Anyone got any ideas?