Sony has released the latest Android Lollipop version starting with the Xperia Z3 and Z2 series. The over-the-air update with build version 23.4.A.0.546 should be available for your Xperia devices anytime now.
Head over to Settings >> About phone>> Software updates>> System updates to check the availability of the new stock firmware. But for some reason if you have missed the OTA notification or, it is yet to hit your region, do not worry as the FTF link for the OTA is available to perform a manual installation on the Z3.
Following is a guide to install stock Lollipop build 23.4.A.0.546 on Xperia Z3 using the Sony FlashTool. This method is also helpful for those who have rooted their Z3, as the OTA will be available for devices with locked bootloaders only.
- The stock firmware used in the guide is compatible with Xperia Z3 D6603 model. Applying this on any other Xperia variant might brick the device.
- Turn the developer rights on. Tap on Menu then Settings and navigate to About Phone. From there tap the build number a few times.
- Enable USB debugging on the phone- navigate to Menu>> Settings>> developer options and check the USB debugging feature.
- Ensure that your Xperia Z3 is having above 80% battery charge.
How to update Xperia Z3 D6603 to Android 5.1.1 stock firmware build 23.4.A.0.546
Step-1: Download the FlashTool file on your PC. Unzip it then install it following the screen prompts
Step-2: Download Android 5.1.1 build 23.4.A.0.546 firmware on your PC
Step-3: Take the .ftf file to the firmwares folder, which is located on the path where you have unzipped the FlashTool
Step-4: Switch off the Xperia Z3
Step-5: Run FlashTool on your the PC and click on Flash
Step-6: You should see prompts asking to connect the phone with the PC. Do not turn the phone on
Step-7: Wait for some time until the update is completed
Step-8: Upon the completion of the process, unplug the phone and reboot it
That's it. You can now enjoy the newest stock Lollipop update on your Z3.