The OS does not match the system requirements of the smartphone.
Where can I find the firmware?
On the official Internet resource of the phone manufacturer.
On sites where developers post custom or official OS.
What should be done before installing the firmware?
Create a backup copy of all personal information: contacts, photos and transfer it to another computer.
Insert your SD card into your phone. It must have enough memory to fit the firmware.
Find information about your smartphone model.
Charge your phone fully.
Download archive with Firmware. Place it on the SD card.
Installing TWRP Recovery
Download the Official TWRP App to your phone from the Play Market. And install this app.
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.
After moving to the next screen, select the 'TWRP FLASH' item and provide the application with root rights.
On the main screen of the application, select 'Select Device', and find 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. Select the file downloaded in the previous step.
Now press the 'FLASH TO RECOVERY' button and confirm your choice, press 'OK'.
After the burn process is complete, the message 'Flash Completed Succsessfuly!' appears. Click 'OK'. The TWRP installation procedure can be considered complete..
Write the firmware to the SD card. Using a PC or laptop card reader.
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. This will delete all user data from the device, but avoid a wide range of software errors and other problems.
Now you can start flashing. Click the 'Install' button.
The file selection screen appears. At the very top is the 'Storage' button, select the location where the firmware file is located.
Select the location where 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, you need to check the item 'Zip signature verification', which will avoid using damaged files during recording.
The procedure for writing files to the device's memory will begin, accompanied by the appearance of inscriptions in the log field and the completion of the progress bar.
The completion of the firmware installation procedure is indicated by the inscription 'Successful'.
Summary: Brand & Model: Ulefone S11; Product Release Date: 09 March, 2019; Fingerprint Sensor: Yes; Waterproof: No; Display Type: IPS capacitive touchscreen; Display Size: 6.1 inches; Resolution: 1440x720 Pixels, 24 bit color depth; Multitouch Input: Yes; Display Colors: 16M Colors; Pixel Density (In PPI): ~ 263.93 PPI Pixel per inch; Touch Screen: Multi Touch Support; Touchscreen Technology: Capacitive; Display Protection: Yes; Features: ~ 263.93 PPI2.5D Curved Glass Screen Capacitive Multi-touch GFF full lamination; Secondary Display: No; Camera Type: Four Camera Set UP (One Front Three Back); Rear Camera: 12MP 5MP 5MP; Image Dimensions: 4032 x 3024 Pixels; Full HD Recording: ...
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