[OnePlus 3T Guides, News, & Discussion] sandeep_kumar:
Hello Friends,

I have seen several Youtube videos and read the thread of xda senior member the rooter to unroot and revert the oneplus 3t to stock. The senior member guided very beautifully to have the stock ROM with or without the bootloader unlocked and fix DM-verity issue.

The following guide is not my invention, I have taken the sources from internet and xda site. The difference is that I used TWRP to flash official oxygenOS zip file of 4.1.6 and I am surprised that this file also flash stock recovery, therefore I did not flash stock recovery and proceeded further for full wipe and lock bootloader. In the middle of thread, I also alerted and said that if stock recovery is not flashed after installing zip of 4.1.6, then it is mandatory to flash stock recovery from fastboot before locking bootloader, otherwise your devices will be bricked.

1) Flash Oxygen OS 4.1.6 through latest TWRP 3.1.1.2 and remember to wipe system, cache, data and delvic cache excluding internal storage before flashing. Do not wipe completely otherwise you will have TWRP installed again and you will have to flash stock recovery through fastboot method.

Link for official TWRP for oneplus 3t: https://dl.twrp.me/oneplus3t/twrp-3.1.1-2-oneplus3t.img.html

Link for official stock recovery for oneplus 3t: http://downloads.oneplus.net/oneplus-3t/oneplus_3t_oxygenos_4.1.7/ , here go down the page and click on "Download Oxygen Recovey (Optional)"

After booting successfully, go to setting and tap the build number 7 times to enable advanced reboot and usb debugging and connect your mobile with your PC and make sure that you have adb drivers installed on your PC.

Now, extract the folder of fastboot and press the right click of mouse while pressing shift button. Basically you have to open command prompts. Now type: adb reboot recovery and hit enter.

2) Your phone should boot into oxygen stock recovery and if it does not boot to stock recovery then flash stock recovery from fastboot.

2) Now your oneplus 3t is having Oxygen OS 4.1.6 with stock recovery but having DM verity issue. Now, full wipe ( select erase everything) in stock recovery and reboot. This wiping through stock recovery may be extra step (locking the bootloader will erase your data completely) but I did this to avoid any problem.

3) Now, sideloaded the same file i.e. oxygen OS 4.1.6 or OOS 4.1.7 through the following command:

adb sideload OTA.zip

where OTA is zip file downloaded from oneplus site for oneplus 3t and renamed it as OTA

(For this, you will have to go to stock recovery and select the option of "install from ADB" then a pop up screen will show you that you are in sideload mode. But remember that sideloading the OS is a slow process; so keep patience and do not remove cable in the middle of installation otherwise your device will be bricked.)

4) Now, lock the bootloader from the command in fastboot mode:

fastboot oem lock

after entering the command in fastboot mode, a confirmation will be asked to lock the bootloader for Yes or No, confirm from the volume keys and let boot the phone automatically and wait to finish.

5) If you sideloaded the OOS 4.1.6 in step 3 then you will see the update notification of OOS 4.1.7 which is about 450MB, download it ,install it and reboot.

6) Enjoy............the stock

Thanks to guides on youtubes and xda site.

Please note that if you follow these steps, you will not have any issues because I have done again and again without any issues but I do not take any responsibility of bricked devices if you perform wrong method or skip any thing.

Please hit the like if find this useful, it is absolutely freeeeee.............