Mecool BB2 2 (not pro) 16 GB DDR3, NAND circuit, flashing successfull and... nothing

[Kirek50]

I have a Mecool BB2 2 / (not pro) 16 GB DDR3 box. After uploading the firmware, atvXperience_v2F_s912 stopped at the logo and that's it.
I performed the steps described here (https://forum.freaktab.com/forum/tv-...box-is-bricked), and with the third USB cable it worked. The box connects to the computer, the firmware flashing is successful, but the box does not respond to the remote control, the blue LED is on and the screen is dark when connected to the tv. I have tried several different firmware and the effect is the same.
What basic files can I flashing to run it?

Maybe there is some rescue firmware, specific files to flashing to recover the bootloader, maybe some other ideas? I will be grateful for any help.

[forart.eu]

I succesfully flashed minislimtv on a Yoka KB2 (Mecool BB2 non-pro clone) and - except 5GHz wifi, wich deadlocks the box - works pretty well:

https://disk.yandex.ru/d/l-7MGfDkTVcjCQ

Hope that helps.