Originally Posted by Marblesnake
That doesn't really help me at all, as I have tried the solutions that what you just posted provides, and none of them have worked. I have tried flashing firefirefire and twrp to the kindle fire using fastboot, but to no avail. I think I need a bit more help than a beginner's guide can provide, but thanks for the link.
First of all, when you try to revert to stock without wiping the necessary partitions, bad things will happen. What usually happens is you end up with some sort of frankenROM with no working shell and no custom bootloader or recovery.
Based on your description, it seems like you aren't in fastboot at all. You can confirm this by paying attention to the boot screen at the device starts up. If you see a bright Kindle Fire logo that stays bright, you're in fastboot. If you see a bright Kindle Fire logo that dims a little after a few seconds, you're no longer in fastboot and the device is trying to boot normally. What usually happens in situations like yours is, not only does the system have no way of booting, but there is also no working shell to send the necessary commands to change the bootmode, and you will receive the typical "system/bin/sh not found" error.
The problem is without a working shell, you cannot get into fastboot to install custom recovery and you cannot install recovery while booted "normally" without a working shell.
You have two options:
* Acquire a factory cable. A Motorola style factory programming cable to be exact. You can purchase one, or make one yourself. There is a thread in the KF General forum with information regarding both. The factory cable will put the device in fastboot so you will be able to install custom recovery and repair your system.
* Use Firekit. But in order for Firekit to work properly in your situation, you need to put the device in USBboot to install a "new" bootloader and recovery. This consists of opening the device and using the "shorting trick" as described in the Firekit thread. I would suggest creating a liveUSB with "persistence" and install the SoupKit. SoupKit comes with Firekit along with a number of other tools you may find useful.
Either way, you need to get custom recovery installed so you can wipe your system and data (factory reset) partitions and flash a new ROM. If it's the stock ROM you want, MoDaCo is your best bet. Once you install a custom ROM, there is no need to "root" as all custom ROMs come pre-rooted.
Hope that helps.