After whole day of waiting, diagnostics mode finally appeared. I removed all files from documents folder using USB device mode and now my Kindle is booting up in less than 2 minutes!
Thanks a lot! What a difference.
I passed the whole procedure with Kubrick but... and now another problem, as usual
I can't quit diagnostics mode. First problem with message "no device_info.xml file" is already solved by creating an empty file device_info.xml. Kindle is than restarting fine and is not displaying error message but it is still entering diagnostics mode after rebooting. Any ideas how to turn it off?
EDIT: I found a topic similar topic
https://www.mobileread.com/forums/sho...d.php?t=171485 and I'm trying with that.