Hello everyone, thank for your support.
I received with pm a link to the image of my kobo. Anyway based on the serial number in the motherboard my kobo should have been v2 (seventh number of the serial is 2) ,anyway the v2 didn't work , just nothing.
So i loaded the v1 and voilą the system work. Not so good because the wifi wasn't able to connect. Non problem i installed offline kobo desktop and tried to make a sync. Nonthing. So i donwloaded an old image (begin 2017) from
https://pgaskin.net/KoboStuff/kobofirmware.html and put that in .kobo folder. The boot process start with an updating and then the system after a few restart worked.
So i would like to thanks you all that helped me to recover my kobo
thanks
Alessandro