[hawhill]

I don't know whether k3flasher will bring real improvements here. You could try it - just to get a different, potentially more verbose error message. My guess is it is in a constant-reboot-loop, an indication we have seen before in some cases. Not entirely sure what this causes, but my guess is on hardware error. (There is the possibility that the battery might not present the right status reporting, but I consider this a rather wild guess that is probably unjustified.)

PS: oh, by the way: the "initial" is a stage where the file you flash doesn't even play a role yet. In that stage, a "loader program" (it is distributed with the ATK) is sent to the kindle and the kindle is made to execute it. Kind of a staged boot-loader, after the very generic "USB downloader" boot loader that is stored in the hardware.