Firmware Aligator S4020 Duo

OS: Android 4.2 Jelly Bean

CPU: MediaTek MT6572, Processor clock: 1.20 GHz, Number of cores: 2, GPU: ARM Mali-400 MP1 @500 MHz

RAM: 256 MB

Display: Color / TFT, 64k colors, 480 x 800 px (4.00") 233 ppi, ~56.9% screen-to-body ratio

Camera: 2 Mpx

Battery: Li-Ion 1350 mAh

Before flashing, you need
Create a full backup of the firmware.
The battery must be 100% charged.

1. Flashing your phone using CWM Recovery
2. Flashing the phone using TWRP Recovery
3. Flashing the phone using Fastboot

1. Phone flashing using CWM Recovery
The rich functionality of CWM Recovery www.clockworkmod.com allows you to perform many manipulations with the device, including rolling the firmware. By default, stock Recovery is installed in the devices, which means that first you need to install the ClockWorkMod Recovery utility itself.
The general firmware process described below is for ZIP files. Instructions: - Download the firmware you are interested in and place it on the phone's SD card.
- Next, turn off your phone.
- Hold down a certain sequence of buttons on the phone body. The set of buttons may differ depending on the manufacturer of your phone. The universal option is to press the following keys.
- Press the Power + Volume up (or Volume Down) (+Home) keys together for a few seconds.
- As a result, the smartphone will boot in Recovery mode (engineering recovery menu).
- Use the volume buttons to navigate through the menus and use the Power button to make your selections.
- Then select 'Wipe data / factory reset' from the menu.
- Use the volume buttons to select 'Yes - delete all user data'.
- From the Recovery mode menu, select 'Wipe cashe partition'.
- Use the volume buttons to select 'Yes - Wipe cache' .
- Highlight 'advanced' and press the Power button.
- Use the volume buttons to select 'Wipe Dalvik Cache'.
- Select 'Yes - Wipe Dalvik Cache' and confirm with the Power button.
Go back, press 'Go Back'.
- Highlight 'mounts and storage' and press the Power button.
- Then select 'format / system' from the menu.
- Select 'Yes - Format' and confirm your choice with the Power button.
Go back, press 'Go Back'.
- Select 'install zip from sdcard' .
- Then select 'choose zip from sdcard' from the menu.
- Select 'Yes - Install your firmware name' and confirm your choice with the Power button.
- Select 'Reboot system now' with the volume buttons and press the Power button.

2. Flashing the phone using TWRP Recovery
For those who prefer working with the utility in the form of TWRP Recovery, the following instructions for the step-by-step installation of the update in the form of a ZIP archive are offered:
- Upload the file with the firmware image to the device's memory.
- Go to TWRP recovery. This is done in the same way as with CWM.
- Perform a factory reset. When cleaning the phone is finished, return to the original menu by pressing the 'Back' key.
- In the main menu, select 'Install' and find the previously downloaded firmware image. Click on it by dragging the slider to the side.
- The flashing process will take about 2-3 minutes.
- After completion, you must click on the 'Reboot System' item, and reboot the device.

3. Flashing the phone using Fastboot
A universal tool for flashing Android smartphones using a PC is the Fastboot utility. It is part of the SDK Platform Tools, which means it is suitable for a large number of devices.
Before starting the firmware, you need to get access to the system kernel. Very often, many manufacturers block this system parameter, not wanting users to change the system files of their firmware images with their own hands. To do this, you need to unblock Bootloader. To do this, you need to study the detailed instructions for configuring and managing the command line. Before starting the firmware using a computer, do not forget to enable USB debugging of the device in the engineering settings of the device.
- Copy the archive with the firmware image to the folder with 'ADB'
- Put your smartphone in fastboot mode and write the prompt in the command line: fastbooflash zip filename.zip, where filename.zip is the name of your firmware.
- Wait until the end of the installation and reboot the device.

Thomas Nilan
Smartphone Expert

Thomas Nilan is a mobile phone expert with in-depth knowledge of the Android and iOS operating systems, who understands the settings of various hidden features that allow you to expand the capabilities of your smartphone, as well as get information about what is going on inside the phone for future repairs. He is an authority in his field, which has allowed him to become a ghostwriter for several technology publications, and he enjoys writing small mobile applications for testing smartphones.