There is an Apple repair program for that issue <a href="http:&#x2F;&#x2F;www.macrumors.com&#x2F;2016&#x2F;02&#x2F;06&#x2F;late-2013-mac-pro-video-issues-repair-program&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.macrumors.com&#x2F;2016&#x2F;02&#x2F;06&#x2F;late-2013-mac-pro-video-...</a><p>Good luck!