Help unbricking a kindle that can't get to ADB

Hi all,

I need some guidance from the experts here. I've read a ton of stuff and tried various things but no lock. I have kindle with FFF 1.4a and TWRP setup. Somehow the SD drive volume is corrupted so I can't load any image (original kindle or twa) to update it. I can't get into adb shell so I can't fix the bad sd volume. however I can get into the bootloader using the usb port and run fastboot. I just need to know how to reflash everything from scratch in the fastboot to get the original kindle, or flash updated TWRP and a good rom.

I have read everywhere but can't see what commands to issue in fastboot to wipe/load the image. I also tried the unbrick utility but no luck. The simple thing I would think would be to fastboot load the full amazon original rom, overwrite everything and then stat over with KFU. I just don't know if I need to replace the boot, the loader, the recovery part, or all of it, and how. If the experts here can give me some guidance and what commands to issue, I would be greatful.

Thanks all

First, sorry for posting in the wrong forum, I didn't realize there was a Q&A section, and can't seem to delete or move the post myself.

SwoRNLeaDejZ, thanks for the reply. I will try that. it will let me update TWRP, but how do I re-flash a whole new ROM with it. ex: if I have the amazon original ROM img which has boot and other sections in it, how do I flash that to overwrite everything? or if i have the twa or some other CM11 image, how can I flash that in with fastboot and basically wipe/replace the boot/system/data/sd card partitions (where the SD card part seems corrupt).

Thanks again

Thanks for the help.

fastboot installing the latest twrp recovery seems to have allowed me to wipe the sd card volume and properly recreate it, so then I can get into adb and push the updated roms. Thanks for everyone's help and sorry to post in the wrong section.