Setup AppleTV 4K with HDR

[technicalpickles]

Got this as part of a DirectTV Now promotion. I tried turning on HDR, but the screen went blank, and never came back on. I unplugged the HDMI cable, and replugged it back in, and it came back on but with SDR. My gear should support it:

• Denon AVR-S920W receiver
• LG OLED55B6P TV

Some resources found so far:

• Apple: About 4K, HDR, and Dolby Vision on your Apple TV 4K
• Denon: Why won’t my cable/satellite box pass 4K content when connected through the A/V receiver?
• PS4 Pro Troubleshooting: How To Display 4K HDR On An LG TV

Some debugging things:

• [x] make sure TV and receiver support HDR10 or Dolby Vision
• [x] make sure using HDMI inputs that support 4k on receiver and TV
• [x] update to latest firmware
• [x] Try to use the shortest distance and highest bandwidth capable HDMI cables possible.
• [ ] Disable Video Conversion for that source
• [x] Try connecting AppleTV directly to TV
• [ ] replace AppleTV to receiver and receiver to TV HDMI cables

4K video, especially HDR10 and Dolby Vision, requires an HDMI cable compatible with these formats. Apple recommends HDMI cables that have the Compatible Dolby Vision mark as they have been tested with Apple TV 4K and a wide range of televisions. An example is the Belkin Ultra High Speed HDMI Cable. With technology constantly changing and the need for higher bandwidth becomes more, we absolutely recommend using 4K certified Cat 5/6 baluns or HDMI over fiber optic.

[technicalpickles]

I got it working 🎉

I replaced the cables, and moved the receiver input to the suggested closest one (CD).

There was a setting to turn on to enable HDR on the TV (settings -> general -> something with hdr in it). I was able to plug in the Apple TV at that point and enable HDR there.

I switched the video input to bypass on the receiver, and that worked when plugging the Apple TV into it. I did try turning it back, so I could get volume display. It might work? Need to test a little more.