Hi Fabio, thanks for the reply.
please find attached the photo of my “beast”...
I found today that LibreELEC RK3238b is working without Shunt Down after a while... the workin image is:
LibreELEC-RK322x.arm-9.2-devel-20200114144630-0bca75f-rk3228b-mk809iv.img.gz
LibreELEC start and everything is working (WiFi, usb, hdmi...).