Firmware BQ Mobile BQ-5521 Strike Power Max

OS: Android 7.0

CPU: MediaTek MT6580

RAM: 1 GB

Display: 5.5"

Camera: double 8, 8 MP

Battery: 4000 mAв‹…h

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 required firmware and copy it to the phone's SD card.
- Turn off your smartphone with the Power button.
- Press a certain combination of buttons on the phone, the combination may vary depending on the manufacturer of the phone. If you do not know the required combination, try pressing the following keys.
- Press and hold the Power + Volume up (or Volume Down) (+Home) buttons together for a few seconds.
- The phone will then boot into Recovery mode.
- Use the volume buttons to navigate the menu, and use the Power button to select.
- From the Recovery mode menu, select 'Wipe data / factory reset'.
- Select 'Yes - delete all user data' from the menu and press the Power button.
- Select 'Wipe cashe partition' from the Recovery mode menu.
- Select 'Yes - Wipe cache' from the menu and press the Power button.
- From the Recovery mode menu select 'advanced' .
- Select 'Wipe Dalvik Cache' from the menu and press the Power button.
- Select 'Yes - Wipe Dalvik Cache' and press the Power button.
Go back, press 'Go Back'.
- From the menu select 'mounts and storage' .
- Select 'format / system' and confirm your choice with the Power button.
- Select 'Yes - Format' and press the Power button.
Go back, press 'Go Back'.
- After that, select the item 'install zip from sdcard' from the menu.
- Choose 'choose zip from sdcard' .
- Select 'Yes - Install your firmware name' and press the Power button.
- Select 'Reboot system now' from the menu.

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:
- Download the required firmware and copy it to the device's SD card.
- Go to TWRP Recovery. This is done according to the model with CWM.
- Perform a factory reset. When the phone has finished cleaning, return to the original menu by pressing the 'Back' key.
- From the main menu select 'Install' and find and select the firmware file. Click on it by dragging the slider to the side.
- The process of flashing the phone will take 2-3 minutes.
- After the completion of the firmware operation, 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.
- First, copy the .zip archive with the image, and place it in the folder with 'ADB'.
- Put your smartphone into fastboot mode and write the prompt in the command line: fastbooflash zip filename.zip.
- Wait for 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.