OnePlus 3 gets OxygenOS 3.2.8
How to install OxygenOS 4.0.1 Nougat firmware on OnePlus 3

OnePlus team has recently started rolling out the Nougat based OxygenOS 4.0.1 over-the-air (OTA) update for OnePlus 3 devices in a phased manner. Consequently, some OnePlus 3 users may still be waiting for the rollout of the new update in their country or region while others could have missed the OTA update notification due to a modified or rooted firmware installed on their handset.

All those users who failed to receive the OxygenOS 4.0.1 update via OTA can now download the same manually, using the step-by-step guide posted below.

Prerequisites

  • Ensure that the USB drivers for the OnePlus 3 are installed on the computer.
  • Keep your phone's original USB cable handy with you.
  • Make sure that you have Developer Options enabled on your handset by navigating to Settings menu. Just tap 7 times on the build number by going to Settings > About Phone and the Developer Options should now be visible in the Settings menu.
  • You can now enable USB Debugging mode via menu > Settings > Developer Options.
  • Verify that your phone's bootloader is unlocked, but not rooted.
  • Ensure that your phone has at least 80% battery charge, before you proceed with the installation.

Downloads Required

OxygenOS 4.0.1 Nougat firmware for OnePlus 3

TWRP recovery for OnePlus 3

Android SDK tool for Windows here, Mac OS X here and Linux here

Steps to install OxygenOS 4.0.1 on OnePlus 3

Method 1

  • Download the OxygenOS 4.0.1 Nougat firmware file on your computer, using the link provided. Also, download the TWRP recovery from the above link.
  • Copy/paste both the downloaded files to the desktop. Then move the TWRP recovery zip file inside the Android SDK folder on your computer.
  • Transfer or move the ROM package files to your phone.
  • Turn on your phone and connect it with your computer, using the USB cable.
  • Launch the command prompt from the Android SDK folder window. Now press and hold the Shift key while right-clicking on the empty space inside the folder.
  • Go back to the command window and enter the following: fastboot flash recovery recovery-name.img.
  • The recovery image should now be installed on your phone. Reboot your phone into recovery mode as follows: Shut down the phone completely by pressing and holding the Power button for a few seconds. Wait until the device turns off and then press and hold Power and Volume Down buttons. Release all the keys when the recovery mode screen appears.
  • Now perform the various wiping functions including wipe data/factory reset, wipe cache partition and wipe dalvik cache (via advanced menu).
  • Finally, hit Install button and select the ROM package from your phone.
  • Swipe once to begin the Nougat update process. Once the update is complete, return to the main recovery menu and hit Reboot.

Method 2

  • Download and save the OxygenOS firmware package to your computer's desktop.
  • Copy this file to the internal storage on your OnePlus 3.
  • Connect the OnePlus 3 to your computer with USB cable.
  • Go to the Android SDK folder on your PC and launch the command prompt window as follows: press and hold the Shift key while right-clicking on the empty space inside the window.
  • Enter the following command to boot into recovery mode via the command prompt interface: "adb reboot recovery", and then hit Enter key.
  • Type in another command in the same window: "adb sideload ROM_name.zip" and hit the Enter key. Note: All the commands must be entered without quotes.
  • The Nougat firmware should now be installed automatically. Reboot the phone once the installation completes.

That's it. You can now run the latest Andrtoid 7.0 Nougat based OxygenOS 4.0.1 firmware on your OnePlus 3.

[Source: Android Geeks]