Did you turn off HDCP? Fixes 99% of my problems

Most PCs don't like to be "set up" on 4K panels. If you haven't set up the computer yet (ie, totally new PC), set it up on an FHD screen before plugging it into a UHD screen.

Also, put an extended warranty on your KS8000- they have a nasty failure rate.

Ask Samsung to change the One Connect cable. I think something is wrong with it. After 3 months of use my tv just stopped to show any signal from the HDMI inputs. And this happened when my new PC ( msi gtx 1080 gaming x card) automatically changed resolution to 4K and the image was gone forever. Something went wrong with the cable. At first they thought my smart hub was the culprit.

I have found HDCP option however no clue on how to disable it. Could it stop the signal completely being sent from the PC to TV?

You referring to the Cable from the HDMI hub to the TV?

Yes. But you can always try another hdmi cable. If you already did that, go for the one connect cable.

Yes cause HDCP is a drm and if the handshake fails or many number of things, it is designed to do exactly that.

This is a late reply.
Found the Issue 2 months ago haha, it turns out my $80 HDMI Belkin Ultimate Series cables didn't have enough bandwidth. Went to Soniq Gold Cables and I now get a 60hz Picture at 4k.

For those buying into Samsung 4k TVs, make sure you buy HDMI cables with more than 18Gbit/s (HDMI 2.0)

Thanks for the help guys/gals.

That wouldn't have been an issue. Any HDMI cable will transfer 4K signals, it just won't be fast enough to properly do it. You would still get an image on screen, there wouldn't be a no signal issue. It's more likely that the belkin cable was bad.