[Nexus 6P Q&A, Help & Troubleshooting] Sabuai:
I am Japanese and speak little English so I used deepl. Please forgive me for the long and difficult to read sentences...

This post was originally written as a question, but now that it's resolved, I'm documenting what I've tried to help anyone else having the same problem I'm having!

I recently inherited a broken Nexus 6P from a friend. I thought it was a cpu failure but apparently not.

symptoms

・If you press and hold the power button and try to start the device as usual, a white Google logo appears, followed by the following warning. The warning will disappear and the white Google logo will glow for a few seconds, then the screen will go blank and the white Google logo will appear again, and the loop will continue until the battery runs out.

⚠

Your device has loaded a different operating system.

Visit this link on another device:

g.co/ABH

・Fastboot will boot normally. When I start recovery mode from there, I get the following warning and then fall into the same loop as described above

⚠

Your device Is corrupt, It can't be trusted and may not work properly.

Visit this link on another device:

g.co/ABH

・The boot loader is locked and if you enter a command it will be rejected because you are not allowed to unlock the OEM lock.

・There are no articles about resolving this symptom, and Google Officials have not posted a solution.

・For this reason, it is not possible to install software by sideloading with ADB or to install a factory image with Fastboot.

Solution

・Force reinstall firmware using Qfil and then install Google factory image

What you need

・Tools to disassemble the nexus 6P

・Something to conduct electricity to short the board (I used tweezers).

・USB-C cable

・Windows PC

・Qfil

・Qpst

・Firmware to install with Qfil (search for Nexus 6P Qfil ROM) I'm not sure why some of them have Android version 5, but that's fine..

ATTENTION

I will not know if you fail and brick or destroy the device. Everything is at your own risk.

IMEI and other information will be lost and the device will only display “unknown”.

This means your Nexus 6P will no longer be usable as a phone.

method

Please install Qfil and Qpst and Qualcomm drivers on your computer beforehand！

Please pre-download both the Rom and Google factory images to be installed with Qfil!

1.Power off the device and remove the rear frame. (You can learn more about how to disassemble the device at ifixit, etc.)

2.Remove the screw securing the plate on the left side of the fingerprint sensor and take out the plate. (If successful you should be able to see three connectors)

3.Connect the USB cable to the PC with the two points on the board indicated by the arrows in the image shorted together

I have uploaded an image of the test point. We will use this test point for this work. Also, do not allow the metal that shorts the test point to come in contact with any metal other than the test point. It is very dangerous.

4.Keep shorting until Qfil recognizes the device. When recognized, it will display Qualcomm HS-USB QDLoader 9008

5.Select FlatBuild. xml, mbn or other files and press the download button. At this time, put your computer in airplane mode and keep it off the network (I don't know if this makes sense, but it worked this way)

If you want to know more about the procedure here, search for other people's articles...

6.Download succeed

Finish Download

If it looks like this, you have succeeded. The device should now be bootable; boot in Fastboot mode (the Fastboot screen will look weird, but it's ok).

7.Enter the following Fastboot command on your computer

fastboot oem unlock

If the device shows LOCKED and nothing else changes, but the PC shows Okay, you have succeeded.

8.Download your favorite version of the factory image from Google. Once downloaded, unzip and run install.bat.

9.The device will automatically restart and resurrection.