Some applications do not open, reinstalling which does not lead to a positive result.
Many applications from the Play Market do not start.
The phone restarts by itself for no reason.
The phone is slow.
The OS does not match the system requirements of the smartphone.
Where can I find the firmware?
On the website of your phone manufacturer.
On specialized services on which various developers lay out custom or official OS.
What should be done before installing the firmware?
Create a backup copy of user data and transfer it to your computer.
Insert an SD card into your phone to write the firmware to it.
Find information about your smartphone model.
Fully charge your device.
Download Firmware and Place it on the SD card.
Installing TWRP Recovery
Install the Official TWRP App from the Play Store on your phone. And run this application.
When you start the application for the first time, you must consent to future manipulations, as well as consent to granting the application Superuser rights. Check the checkboxes and press the 'OK' button.
On the next screen, you need to select the 'TWRP FLASH' item and give the application root-rights.
On the main screen of the application, select 'Select Device', and find your phone model.
After selecting a phone, the application will direct the user to a web page to download the modified recovery environment image file. Download the proposed *.img file.
When the file is loaded, you need to return to the main screen of the Official TWRP App and press the 'Select a file to flash' button. Select the file downloaded in the previous step.
Click the 'FLASH TO RECOVERY' button and confirm your choice, click 'OK' in the question window.
After the burn process is complete, the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure can be considered complete..
Transfer the firmware and other necessary files to the SD card.
Insert a SD memory card into the phone.
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. We open the menu, select the 'Reboot' item, and then click on the 'REBOOT RECOVERY' button. The phone will reboot into the recovery environment automatically.
Firmware via TWRP
Before flashing, you need to clear the 'Cache' and 'Data' sections, press 'WIPE' on the main screen. You will delete all user data from the phone, this will avoid software errors and other problems.
Now you can start flashing. Click the 'Install' button.
The file selection screen is displayed. At the very top is the 'Storage' button, which allows you to switch between types of memory.
Select the storage to which the files were copied. Press the OK button.
Select the firmware file 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 writing files to the phone's memory will begin, this is accompanied by the appearance of inscriptions in the log field and the movement of the progress bar.
The completion of the firmware installation procedure is indicated by the inscription 'Successful'.