I have the Sapphire r9 290x and I've been mining with cgminer just fine for a few weeks. I decided to give sgminer a go and after starting up the screen immediately goes black. I can start windows fine but after about 30 seconds the screen goes black again. I have tried everything... I restored to a couple days ago, i disabled all startup applications. I started in safe mode. This happened to me a few days ago and somehow I fixed it but I tried running sgminer again and the same thing happened. Any ideas why or how to fix it?