I’m running CoreELEC 21.2-Omega_nightly_20250505 (I have also tried to update to the latest 20250919 version, but currently I reinstalled an older version just to try) on a Ugoos AM6B+.
Setup: Ugoos → Onkyo TX-RZ50 AVR → Projector.
The issue: Even though I can watch 720p and 1080p video files and diffrent frame rates (23.97→23Hz, 24→24Hz, 25→50Hz, 29.9/30→60Hz, 50Hz, 59.9/60→60Hz), but when ever I try to play any 4K HDR/SDR video the screen goes black to switch the frame rate for longer than usual, then nothing happens, Blue screen (No signal). This only happens with 4K HDR/SDR, 4K Dolby Vision movies play just fine and the frame rate switches to 23 or 24 Hz just fine.
Issue:
1080p and 4K Dolby Vision files play fine, refresh rate switching works.
Any 4K non-Dolby Vision file (Any SDR or HDR) = Blue screen/no audio (AVR shows “No Signal”), but playback continues in Kodi (confirmed via web remote) and I stop the playback using the web remote then the signal comes back to kodi home menu screen.
Forcing 8-bit output in CE makes 4K play.
Even 8-bit SDR 4K files fail unless I force 8-bit globally.
Direct connection Ugoos → Projector works fine (all 4K modes at 10/12-bit).
Some workarounds that somewhat worked but didn’t fix the issue:
Forcing 8-Bit color depth (But then what is the point of buying the Ugoos if I won’t be able to watch my movies at the highest quality)
Turned off refresh rate switching, which made me able to play all 4K SDR/HDR files, but they were playing at 1080p 60Hz, which is the GUI resolution (When I tried to change the GUI resolution to 4K I lost signal untill it changed back to 1080p since I didn’t press keep changes).
Trying to whitelist some options is a hit or miss, the only way I got it to somewhat work is by white listing (4K 50fps, 4K 60fps) and enable doubling frames, then I am able to play 25fps→50Hz, 29/30fps→60Hz, but 23.97/24 play at 60Hz even when I don’t enable 2:3 pull down. If I try to whitelist 4K 23.97fps or 24fps, it doesn’t work and the No signal comes back.
I really want to make the Ugoos my go to device to watch my 4k blurays in the highest quality possible, I have never owned a bluray player, as I said.. any 4k with DV plays perfectly even with FEL, but if the 4k disc is 4K HDR10 and I try to play it, No signal appears, and I’ll have to either force 8-Bit, or watch it at 60Hz with its stuttering. I really don’t know what to do, I have been wrapping my head around this issue for the last two months! Please help
I have “Original Ugoos AM6B Plus Amlogic S922X-J 2.2GHZ TV BOX WIFI6 Android 9 4GB RAM 32GB ROM 4K Media Player 2.4/5G 1000M Set Top Box”
It works fine when I plug it directly to the projector or when I plug it to my other Lg tv.
Could it be possible that you do a backup “excluding thumbnails and so on” so I could try to restore on my device? I don’t know if it’ll even work since I did a full reinstall on another USB stick. But after two months I wam willing to try anything.
Is there a way to force reset the EDID? Could it be because I was using the device directly connected to the projector for a few months then I connected it to the AVR?
I have only reinstalled CE by pressing the reset pin, should I have also formatted the android OS it self?
After Talking to ChatGPT, Gemini, Claude, Perplexity.
And comparing “cat /sys/class/amhdmitx/amhdmitx0/disp_cap” and “cat /sys/class/amhdmitx/amhdmitx0/disp_cap” outputs between the Ugoos plugged directly to the Projector and through the AVR, I came to zero conclusions.
I also tried turning off Deep Color option on the AVR (Hold STM button then press On/StandBy) which made me able to play the 4K SDR/HDR 10bit movies, but the Projector detected them as 8-Bit, which is basicly the same as forcing 8Bit.
So when I wanted to turn Deep color back on, I pressed CBL+StandBy, which formated the AVR, which kinda fixed the issue, I still don’t know what option in the AVR was the reason, but now.
Now all media can be played, but the projector detects everything as 12-Bit, except DV movies which report as 8Bit.
Have you enabled ”enhanced” mode in Onkyo hdmi settings? Set Kodi gui to 1080 50/60hz and reset whitelist settings in Kodi. Power off all and power on again after some time
Thanks for the suggestions, but as I said in the original post, yes I have indeed tried 4K enhanced instead of standard, I even tried 8K enhanced, and the GUI is alread set to 1080p 60Hz. And I have Power everything Off and On till I lost count.
This is not my case, I know that DV tunnels everything as 8-Bit that’s why DV is working just fine, what my issue is that when I play 10-Bit 4K SDR/HDR, I get No signal.
Thanks, I’ll try using Arc instead of eARC or even turn it off all together, but definitely won’t just throw away my new 1800$ AVR and just buy another.
I think you’re misunderstanding pass-through on Kodi. That option (enabled) will bitstream the various Dolby/DTS formats to the AVR. If you disable pass-through, then Kodi will decode as best it can and send LPCM or will transcode to whatever other option you set.
I am asking here because this issue is only happening with the Ugoos, when connecting the PS5 to the AVR it outputs 4K HDR 12bit just fine. I even tried a cheap Xiaomi box and it played 10Bit HDR videos no problem.
Hey, thanks for the suggestions and clarification, I meant exactly what you said by kodi converting TRUEHD to lossless LPCM, but I used the wrong terms, so will it also include Atmos ceiling channels in the LPCM conversion or just the bed layer only?
I tried multiple certified HDMI cables, I tried disabling eARC all together, and I also tried disabling audio pass through, unfortunately none of these worked.
When plugging a PS5 using the same exact port on the AVR, same HDMI cable, outputs 12 bits just fine.
Just the main layers would be converted to PCM if not in passthrough mode. If you use passthrough, then the AVR will decode, providing it has the appropriate licence / capability to extract the Atmos data.