[Fire HD 8 and HD 10 Original Android Development] Barron Arrow:
TO RECAP...

I originally rooted my Amazon Fire HD 10, 2017 (Suez) model tablet using instructions that I found online here that were based on a XDA post by

Ratyre. https://github.com/3ch01c/3ch01c.github.io/blob/master/docs/how-to-setup-amazon-fire-hd10.md

They are excellent instructions with solid software download links. I was able to root my tablet but this method did not unlock the bootloader and I could not install a custom OS.

At this point I made 3 big mistakes...

1. Installed the "Original TWRP App" and tried to flash a TWRP recovery that I had found in one of the sets of instructions. I ended up damaging the "recovery" mode somehow and could no longer access it. (I could still get into fastboot by using the command "adb reboot bootloader" in Windows command prompt)

2. Next I tried following the instructions in this post and installed a Ubuntu terminal program for Windows. Somehow I ended up with two copies of "adb" embedded in Terminal. This kept giving me errors when I would try to run the "sudo ./step-1.sh" script.

adb server version (41) does not match this client (39); killing... I thought that these instructions were not working because of this error (smithbill let me know that I had inadvertently installed two copies of "adb" causing this error)

3. I installed the Majisk app through Command Prompt and ran it on the tablet. (thinking it would unlock the bootloader, doesn't work unless originally installed in TWRP) I followed the app instructions to install it and restart the tablet.

WHEN IT RESTARTED I WAS STUCK IN A BOOTLOOP WITH NO ACCESS TO RECOVERY MODE OR FASTBOOT.

THE FIX:

To fix this I had to follow the unbrick #2 instructions for the second post on this thread.

1. I downloaded a copy of Linux Mint to create duel-boot laptop. (messed my laptop up first time, Linux did not recognized installed Windows and destroyed Windows bootloader) re-installed windows and followed these instructions to create duel-boot

https://itsfoss.com/guide-install-linux-mint-16-dual-boot-windows/

2. Opened up my tablet. (scary) Removed micro memory card. Worked thin screwdriver into the side of the cover and gave a small twist to pop it open. Worked my way around the entire tablet gently twisting until the back cover came off. Removed tape from power connection and video cable. Detached video cable by lifting up black thingy to loosen it up, and then gently pulled on the loose plastic hanging part on top of the display cable. Removed power cable by lifting up on the part that connects to the mother board. Removed all of the screws holding the mother board to the tablet. Hint: Be sure to take a picture of everything before you start to take it apart (had to order a new set of star bits that were small enough to fit into the screws. https://www.amazon.com/gp/product/B087V5RKHN/ ) Removed the mother board by gently loosing the speaker and on/off wires and then gently loosening the two small black plastic tabs holding it in place. (I wish I had taken a picture of this)

3. Booted into Linux Mint. Opened a terminal and ran these commands:

sudo apt update

sudo add-apt-repository universe

sudo apt install python3 python3-serial adb fastboot dos2unix

Then these commands:

sudo apt-get remove modemmanager

sudo apt-get remove --auto-remove modemmanager

sudo systemctl stop ModemManager.service

Next, made sure that USB cable was not attached to the motherboard. I opened a Linux terminal in previously downloaded amonet folder from the first post in this thread. (open amonet folder in file explorer, right click and then click on "Open a terminal in this folder")

Then used this command:

sudo ./bootrom-step.sh

My terminal prompt said something like "waiting for device"

Next, I used a bread bag twisty tie to short the motherboard. I stripped a little of the paper off of each end to reveal the metal inside. I gently worked one end into the memory card reader slot for my ground. Then I touched the point on the motherboard that shorts it out. (There is a picture of the proper spot on this guide https://xdaforums.com/t/2017-fire-hd-10-unbricking-from-anti-rollback.3896616/)

I removed the short when prompted to do so and let the computer do its thing.

After it worked successfully, I followed the directions, putting the mother-board back and reconnecting the power cable and monitor ribbon. I used my finger-nail to power on the tablet, and once I saw that it was working put it back together again. (cover and all)

When it was turned on it booted into fastboot mode. I re-connected the cable and ran this script in the terminal...

sudo ./fastboot-step.sh

And my tablet rebooted into TWRP

I MADE A PRETTY BIG MISTAKE AT THIS POINT. I used TWRP to wipe tablet memory and then MISTAKENLY hit "reboot tablet" instead of pushing the back arrow and then swiping "Swipe to Factory Reset" like I was supposed to. My tablet rebooted and got stuck on the white Amazon logo. ;'P I HAD TO TAKE IT APART ALL OVER AGAIN! BOOOOO!

After taking it apart again I downloaded the 12.1 version of the XDA created operating system to my computer... https://xdaforums.com/t/discontinued-rom-unlocked-suez-lineage-12-1-05-may-2020.3953677/

Then I downloaded a copy of the Magisk-v23.0.apk and renamed it Magisk-v23.0.zip.

I also downloaded a copy of GAPPS Nano from google (ARM64, 5.1, Nano) https://opengapps.org/ (Nano was the only version small enough to install on the tablet)

I put all of these downloads in a new folder on my memory card and then inserted the memory card back into my tablet.

This time when I booted into TWRP I went to WIPE>Format Data>Typed "yes" to wipe the data. THEN PUSHED BACK ARROW AND THEN "Swipe to Factory Reset"

Next I pushed the back arrow and pushed Install. I hit "Select Storage" and selected my memory card. First I selected the new 12.1 OS and swiped to install. after installing it I "Swipe to clear cash." I did the same thing with the Majisk zip and GAPPs zip.

Next I hit "Reboot" and I had a new operating system installed on the tablet. :)

I'm still able to get back into TWRP by connecting the tablet to my computer, opening the command prompt (in Windows) and typing

adb reboot recovery

Enjoy!View attachment 5422643