Originally Posted by SantaF0x
It was definitely set to "Enhanced" because yesterday when I did a factory reset to Marantz unit and HDMI started to work, this setting was dropped to its default "Standard" state, and it was easily recognized by inaccurate colors. After this I set it to "Enhanced", checked that Shield found the connection as "HDR10 compatible", and Samsung TV displayed "HDR UHD" in status line.
Ok, there's small update on above. I had a little time yesterday to play with all this stuff, but what I did:
1) turned off: on Samsung Q90R - Anynet+, on Marantz - all HDMI settings (no passthrough, no HDMI control, no ARC), Shield - CEC control off.
Shield display output and Marantz GUI appeared, so the issue is not connected to "Enhanced" 4K setting. With Shield turned off and its input selected, TV says that there is no signal. Ok, it's logical.
2) I turned on ARC in Marantz HDMI settings (passthrough is still off, HDMI control is off) and Anynet+ on TV.
Everything continue to work, simple CEC control also started to work between TV and AVR (sound volume control).
So only two settings was left off: HDMI passthrough and HDMI control. I will do more testing, but it seems that the problem lies beneath one of them, and I bet it is "passthrough".