Cosmote tvbox dtb?

I got a cosmote tvbox which made by skyworth digitals.the SOC is s905x4-bu ,in android support dolby vision.the motherboard vision is hy44g.
i got the and unzip the payload.bin.and use extract-dtb tool to get a dtb file.but neither adb methord nor methord cannot work.the screen stay black till i disconnect the usb storage.
here is the link
, thx in advance for any help.

You need to test if CoreELEC boots at all. Skyworth is known not support third party systems at all.