[Shield Android TV Q&A, Help & Troubleshooting] Hugonow:
Hey guys.

After the time I spent trying to unbrick my softbricked shield 2015 16gb, I decided to share how I was able to solve it.

I was on 5.2 and decided to update to 6.1 since the developer image was released and my previous upgrade from 5.1 to 5.2 with flashfire run so smoothly so what could go wrong??

After install lastest flashfire 0.73, I select all but data on the flash firmware package, and let it run.

I had my shield on 5.2 rooted and with TWRP as recovery.

After flashing vendor.img it restart and get stucked on the nvidia logo, and there was where

my problems started.

After 30 min I switched off and on again and same thing. Nvidia logo and nothing more. 1 hour after that I finally was able to go into bootloader mode.

I needed to use the default USB cable that came with the shield connected to OTG and USB on my computer. As soon as I connect the power and the led goes on I pressed the power button until I was

able to see the menu.

From there I was able to run fastboot. I reinstall every build and the shield refused to back to life. Flashed successfully but wont go through nvidia logo.

I enter recovery and did a reset assuming I had some problem with my data. No luck. I start to assume my shield has a hardware problem.

I downloaded both the stock recovery and the developer image 6.1, 6.0, 5.2, 5.1.

Tried to flash all of them one by one. Nothing worked. It complete the flash process but after reboot keep stucked on the logo.

Lots of time reading XDA and googling it I found a TWRP 5.1 flashable zip image, and in last resort I download it, reflash TWRP and flashed the 5.1 zip image.

It worked!!

I run the wizard as a new shield, and return to TWRP and flashed SuperSu 2.79. Rebooted, and install flashfire and run again the process with the 6.1 developer image.

This time flashed ok, and I finally get 6.1 rooted and working perfectly.

So resuming all the steps for those who dont want to read all :P

If you are stuck on Nvidia logo after flash 6.1

1 - Download firmware 5.1 zip TWRP flashable (search on XDA)

2 - enter bootloader on your shield hardware mode. Connect the OTG port on Shield using the default USB cable, and after connecting the power and the green light turn on press the power button until the bootloader menu appears.

3 - Assuming you already had the shield drivers and ADB installed on your computer, go to TWRP recovery or install it. I flashed TWRP 3.02 (once again search for it on XDA). fastboot flash recovery "twrp filename.img"

4 - Boot to TWRP and upload the firmware with the command adb push "firmware filename.zip" /sdcard/

5 - Upload also the SuperSu 2.79 binaries. adb push "supersu filename" /sdcard/

5 - from TWRP install the firmware and let it run. It will generate some errors but it will work.

6 - Reboot and complete the wizard.

7 - Reboot to TWRP (you can activating developer mode, and run adb reboot recovery from inside the androidsytem) and flash the SuperSU

8 - Reboot again and install the latest flashfire.

9 - Download the 6.1 developer image (search XDA for it)

10- Run flashfire and install the firmware package. Thats it!

:)

Hope this will help someone