There is an Apple repair program for that issue http://www.macrumors.com/2016/02/06/late-2013-mac-pro-video-issues-repair-program/ http://www.macrumors.com/2016

There is an Apple repair program for that issue http://www.macrumors.com/2016/02/06/late-2013-mac-pro-video-issues-repair-program/ http://www.macrumors.com/2016/02/06/late-2013-mac-pro-video-... Good luck!