Thanks for your support.
I have tried holding my finger on upper left screen then plug in thencqble, it did not work.
Then I tried, what I did before. With the first try it found the device and has flashed the firmware!!!
Now I can also download maps in Garmin Express.
This I did, but when I disconnect and connect again to laptopp, GarminExpress asks me again to update maps and software...
What shall I do now in the mass storage mode? Any files to change or repair? Shall I run webupdater? Or just flashin original firmware?

Edit:
Solved. Formatted device and followed unbrick thread. Thx