Originally Posted by Mike76
I've succesfully debricked my K4NT Black SO using the "Small debricking guide for noobs" guide and 4.0.0 kernel images. (At first I' tried 4.0.1 images, but the Kindle doesn't boot up for some reason.) It's not perfect - it can't connect to my Amazon account, and I'm not able to update the firmware nor to 4.0.1, neither to 4.1.0, but it's usable.
It was reported that the 4.0.0 image contains a screensaver hack that needs to be removed so you can update the firmware. You should be able to rename the "800x600" folders to do that manually... You should be able to connect to amazon. Perhaps you need to factory reset and re-register?