All smartphones provide options to upgrade their Android Operating system through System Update. But sometimes update fails to download or install downloaded firmware. In such cases, you can manually update your Android Smartphone using OTA update zip file. This tutorial shows, “how to update/upgrade your Android smartphone” using Firmware zip file via Recovery mode.
Requirements to Upgrade
1. Official Stock ROM / Update.zip file for your smartphone.
2. Take Backup of your personal data as this process will erase all data on your phone.
3. Charge your phone’s battery more than 70%.
How to Upgrade your Android smartphone
Copy downloaded Stock ROM (Firmware) zip file to your SD card and rename it to Update.zip. Insert SD card in your phone.
After you have inserted SD card in your phone. Power off your device using power button on your phone.
Now go to Recovery Mode by holding down volume up, volume down, and power button together. You should hold these three buttons for 10 seconds and then release. You should see Android robot logo, if you don’t see it, you have to power off your device again and repeat this step again.
You will see Recovery Menu on screen, choose wipe data/factory reset and wipe cache partition before installing OTA update zip file on your device.
After wiping out data and cache partition, select apply update from sd card and then navigate to firmware ROM zip file you copied to your SD card in Step 1 and select it.
This process is going to take some time. You can have a cup of coffee in meanwhile.
After you have successfully installed OTA update on your Android smartphone, choose reboot system now option from Stock Recovery Menu.
Now, your smartphone will reboot and will start with delay for first time. And your Apps will be optimized for new upgraded Android OS. If you face any issues with upgrade, reset your Android smartphone to factory settings. This might solve most of the problems.