[zigo]

Originally Posted by salamanderjuice

It's the cable connecting the display to the motherboard. You'd have to open the device to check.

https://www.ifixit.com/Teardown/Kobo...eardown/139831

Originally Posted by Quoth

The connector locking clip is easy to break on some ribbon cable assemblies. Some push back and some tilt.

Thankyou very much. I'll keep opening it as a last resort.
Before I want try another solution if possible: if the display is broken (probable, because if I correctly remember days ago is fallen down) anyway the great part of it works correctly (the area on the right who is about 10 cm x 15 cm).
It should be possible configure the OS to use that part of the display only (like is possible on some monitors), modifying Kobo eReader.conf or other configuration files? Or using alternatives OS?
Thanks in advance!
rob