I have two CoreELEC based devices, Minix T5 and Tanix TX9S. The latter has no issues whatsoever handling FullHD and 4K resolutions at any frame rate. Minix however, does not play well with 4K with frame rates like 23.98, 24 or 25. When I select the UI to be displayed in 4K, say 24fps, or whitelist that combination and play matching content the screen goes blank. At first I though the issue was my Sony (which is a definition of an issue) but Tanix works just fine with these parameters.
Does anyone have similar experience?
Either your HDMI cable can’t handle the bandwidth required by 4K @ 24-30Hz (most likely) or it is your TV.
I’d suggest replacing the cable with a high-speed premium certified HDMI cable.
But as a potential quick fix, which shouldn’t affect image quality, you can enable the 4:2:2 chroma option in CoreELEC settings, then reboot and try again.
I don’t think it has anything to do anything with cable. It’s 2.1 HDMI certified and works just fine with higher frame rates (say 4K@50 fps). As I said Tanix works just fine with any framerate, so I don’t think it’s TV’s fault neither.
I did try 4:2:2 downsampling but it yielded a blank screen. I don’t think though it would make any difference, IUUIC it reduces the quality so it could fix the higher framerates not being displayed correctly, not the other way.
Sorted it out! I connected the Minix via AVR (previously I was using it only to play sound from ARC) and all the resolutions/framerates work. Bonus is that DtsHD and TrueHD sound modes work as well.