Errors periodically appear in the Android operating system.
Some applications stop opening.
Some applications from the Play Market do not start.
The phone restarts or shuts down for no reason.
The phone began to slow down a lot.
You have decided to try a different version of Android.
Where can I find the firmware?
On the official website of the manufacturer.
On certain sites where developers post custom or official OS.
What should be done before installing the firmware?
Create a backup copy of user data and transfer it to another medium.
Insert your SD card into your phone. An SD card is needed to write firmware to it.
Find out the exact model of your smartphone.
Fully charge your device's battery.
Find and download the archive with Firmware. And place it on the SD card.
Installing TWRP Recovery
Download the Official TWRP App from the Play Market. Download, install and launch the application..
When you start the application for the first time, you need to give consent to future manipulations, as well as to give consent to granting the application Superuser rights and click the 'OK' button.
In the next screen, select the item 'TWRP FLASH' and provide the application with root-rights.
On the main screen of the application, click on the 'Select Device' drop-down list, and select your phone model.
After selecting the phone, the application will redirect the user to a web page to download the modified recovery environment image file. Download the proposed *.img file.
After downloading the image file, return to the main screen of the Official TWRP App and press the 'Select a file to flash' button. Then we tell the program the path where the file loaded in the previous step is located.
Press the 'FLASH TO RECOVERY' button and confirm that you are ready to start the procedure - press 'OK' in the question window.
When the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure can be considered complete.
Transfer the necessary files to the SD card. Using a PC or laptop card reader.
Insert a memory card into the device.
To reboot into recovery, you need to use a special item in the Official TWRP App menu, accessible by pressing the button with three stripes in the upper left corner of the main screen of the application. Open the menu and select the 'Reboot' item, and then click on the 'REBOOT RECOVERY' button.
Firmware via TWRP
Before flashing, you need to delete all user data from the phone, this will avoid errors in the software, as well as other problems. Press 'WIPE' on the home screen.
Press the 'Install' button to start the flashing.
The file selection screen is displayed. At the very top is the 'Storage' button, select the location where the firmware file is located.
Select the location where you copied the files. Press the OK button.
Find the file we need and click on it. A screen opens with a warning about possible negative consequences, as well as the item 'Zip signature verification'. This item should be checked by placing a cross in the check-box, which will avoid using damaged files when writing to the phone's memory sections.
The procedure for flashing the phone will begin, this is accompanied by the appearance of inscriptions in the log field and the movement of the progress bar.
After completing the installation procedure, a 'Successful' message appears on the screen.