Unknown s905d dvb-t2 box

Hi,

I have such a box on my table, it is s905d dvb-t2 version. Do you know what it is and how to flash it with coreelec, libreelec or some other ROM?
Now it is not working. Or do you have original ROM?
In Amlogic_USB_Burning_Tool_v2.2.0 is the device visible.

There are these chips:

wifi realtek: rtl8189es
2x ram (size not known): 51a47 d9vct mka711000a rt50f
emmc (size not known): ems1ascbt1fc008 ->8GB?

And it is recognised as:

USB\VID_1B8E&PID_C003
WorldCup Device

After connecting to UART, there is

GXL:BL1:9ac50e:a1974b;FEAT:ADFC318C;POC:3;RCY:0;EMMC:0;READ:800;SD:800;USB:8;LOOP:1;EMMC:800;NAND:81;SD:800;USB:8;LOOP2… and loops again.

For an advice I will be welcome. Thanks

standal