I have an Asrock J5005-itx board with Windows 10 home and a samsung NU8000 UHD tv. If I leave the "HDMI UHD color" set to off on the TV, then I can display 4K @ 60Hz at 4:2:0 color, which has blurry edges on text. 4K @ 30Hz 4:4:4 works fine.
When I switch the samsung to have HDMI UHD color ON, then the signal is dropped and no image shows. With the UHD color on, the tv should support 4K @ 60Hz with 4:4:4 at 8-bit, but I cannot get this to work.
I would like to know if there are any graphics driver updates which might address this issue.