[Nexus 6  General] K!ngpen:
If your stupid like me :silly: and you blindly follow the [HOW-TO] The Nexus 6 All-In-One Beginner's Guide you may be trying to figure out how to fix your phone. :eek:

The beginner guide linked above is amazing to say the least but the OP has not updated it yet to reflect the 6.0 update. If your phone has Marshmallow 6.0 and you follow the instructions you will render your Nexus 6 unusable. Not bricked, just not functional. You will get an error that states Your device is corrupt. It can't be trusted and may not work properly. (seen below) Followed by a blank screen. But don't worry, its very easy to fix with just a few extra steps. :fingers-crossed:

If you are here, it is assumed that you have already done the following steps:

Step 0.1 Download and install the Android SDK tools (adb and fastboot), as well as the Google USB drivers. This is step 2 in the beginner guide and there is a great write up here on these tools. [noob-read] adb and fastboot. What is it? How can it help you?

Step 0.2 Unlocked the Bootloader.

Step 0.3 Ran the CF-Root tool. The file name is CF-Auto-Root-shamu-shamu-nexus6.zip

If you watched the CMD window closely this is where the problem happened. There will be a couple errors thrown. You will wait to see the big red Android on your phone but instead you will see the above warning message flash briefly followed by a black screen. If this is the case, proceed to step 1​

Please Note: Parts of these steps are copied and pasted from other instructions. Consider this a grouping of other instructions for the purpose of simplification. :rolleyes:

Step 1 - Install a Custom Recovery (taken from the original guide)

Go HERE to download the latest TWRP recovery for the Nexus 6. At the time of this write-up, I used 2.8.5.0

Turn the phone off. Then boot it into the bootloader/fastboot mode by holding volume down + power.

Rename the recovery file that you downloaded above to recovery.img. *Make sure that you rename it to recovery.img NOT recovery.img.img

Move the recovery.img file to C:\Program Files (x86)\Android\android-sdk\platform-tools

Open command prompt and run the following commands:

cd C:\Program Files (x86)\Android\android-sdk\platform-tools

fastboot flash recovery recovery.img

On the phone, use the volume buttons to scroll onto "Restart Bootloader" and hit power to select it.

After the bootloader reloads, use the volume buttons to scroll onto "Recovery Mode" and power to select it. You should then be greeted with your newly installed custom recovery.

Power off the phone

Step 2 - Install the Modified boot.img (Original steps HERE)

Download the modified boot.img from http://downloadmirror.co/android/sx/shamu-mra58k-boot.zip

Unzip the file and move it to C:\Program Files (x86)\Android\android-sdk\platform-tools

Boot the phone back into bootload mode using Power + volume down.

Open a command prompt and enter the following commands:

cd C:\Program Files (x86)\Android\android-sdk\platform-tools

fastboot flash boot boot.img

Power off the phone

Step 3 - Flash the SuperSU zip via TWRP Recovery v2.56 beta (original steps HERE)

Downlaod SuperSU x2.56 from http://downloadmirror.co/android/u1/SuperSU-v2.56-20151030013730.zip

Boot your phone into the bootloader mode with Power + volume down

Enter recovery mode. This will open TWRP Recovery

After TWRP Recovery is open, connect your phone to your computer.

Open My Computer where youc an see the C: drive, and other connected drives. You should see your Nexus 6 listed. Open it.

Move the SuperSU zip onto your phone. I placed mine in the TWRP folder.

On your phone, select Install, then navigate to the folder that contains the SuperSU zip. Click on the zip file.

Swipe to Confirm Flash and begin the flash.

Once SuperSU is flashed, select the Reboot System option.

And that's it, your phone should now boot back up to your fresh rooted copy of Android Marshmallow 6.0. You can download a root verification app to confirm the root. :victory: