Originally Posted by geekmaster
WARNING: Although fastboot seems to flash partitions correctly on a K4NT, according to serial port messages while flashing various partitions on the Touch, it always writes to mmcblk0 instead, which destroys the linux kernels for both the main and diags partitions. More evidence is that after I flashed mmcblk0p4 with a "filled in" version (I cannot export the USB drive), it now reports "cannot find linux kernel" when trying to boot main or diags. Both linux kernels are in mmcblk0p1, which is what appears to get damaged when you try to flash anything else. This is also probably why it finishes so quickly.
Ok! So this is now the most plausible explanation for my Kindle's symptoms following running "sudo ./fastboot erase data". Which to recap, are a completely black screen and no USB drive, which goes into HID mode and responds to the MfgTool but doesn't go into diagnostic mode, and shows signs of going into fastboot mode but doesn't respond to the fastboot tool. Instead of erasing /var/local (to repair a full /var/local/) perhaps that command blitzed those two partitions, main and diags. Not sure about the fastboot symptom. So it's in pretty bad shape, but I'm hoping there is still something I can try using MfgTool - which is, again, literally the only way I can communicate with the Kindle at this point. (barring perhaps the serial port)
Thanks for the tip about power - I bought a power adapter and charged it overnight and now it doesn't keep going to the charging screen. Interestingly, it only seems to charge on the charging screen and when the kindle is turned off, not in black screen mode). No other changes in behaviour, but given the symptoms you describe that could easily have been the problem so good to rule it out.