OnePlus recently released its first Android 7.0 beta build for the OnePlus 3 via OxygenOS Open Beta 8. The performance of Nougat on OnePlus 3 is very impressive. However, some users are not happy with it and want to downgrade their OnePlus 3 to Marshmallow (OxygenOS 3.2.8) from Nougat (OxygenOS open Beta 8). Unfortunately, once you flashed the OxygenOS Open Beta 8 (Android Nougat) on OnePlus 3, you will not be able to downgrade to Marshmallow directly.
In this tutorial, we show you how to downgrade OnePlus 3 to Marshmallow from Nougat. That is, you can downgrade OnePlus 3 to OxygenOS 3.2.8 from OxygenOS Open Beta 8. Currently, there is official way to downgrade OnePlus 3 to OxygenOS 3.2.8 (Android 6.0.1 Marshmallow), but there is a simple workaround to do that. Read on to know how it is.
Thanks to the XDA senior member Mina Mngawy for the workaround, that lets you easily downgrade OnePlus 3 from Android Nougat to Marshmallow (from OxygenOS Open beta 8 to OxygenOS 3.2.8).
Before start, note that the below given method is unofficial. If you are looking for official way to downgrade OnePlus 3 to Marshmallow from Nougat, contact OnePlus customer support (recommended).
– OnePlus 3 should be bootloader unlocked and running on OxygenOS Open Beta 8
– Backup every data you have on the phone
– At least 80% battery charge remaining on the phone
Disclaimer: Follow the instruction at your own risk. We will not be liable if any damage occurs to your device and/or its components. It is recommended for technically talented users only.
Required files to downgrade OnePlus 3 to Marshmallow:
1. Flash the modified TWRP for OnePlus 3 via Fastboot.
2. Reboot your device into TWRP Recovery mode. It will ask for password to decrypt your data. Just cancel or skip and allow modifications on system
3. Go to Mount and mount system.
4. Now, go to Wipe > Advanced wipe > select system > Repair or Change File System > Change File System > EXT4
5. Go back to Wipe section, and select Format Data.
6. Again go to Wipe > Advanced Wipe > select everything except ‘USB-OTG’ and swipe to confirm it. Then reboot your device to recovery again.
7. Connect your device to computer and without leaving TWRP, transfer the OxygenOS 3.2.8 zip to your device over MTP. Then, go ‘Install’, locate the ROM zip file and swipe to install it.
8. Once done, reboot your device to bootloader mode.
[Now, you need to flash the downloaded stock recovery image via Fastboot. Follow the instruction below]
9. Rename the stock recovery image as ‘recovery.img’ and save it in the ADB installation folder
10. Open a command window inside the ADB installation directory and issue the below command:
fastboot flash recovery recovery.img
11. Now, reboot your device into stock recovery.
12. In recovery, do a factory reset and restart your phone.
Your OnePlus 3 now downgraded to OxygenOS 3.2.8 from OxygenOS Open Beta 8. If you have any questions, leave it in the comment section below. (source – XDA)