The process of flashing a smartphone Android often becomes the only way to bring the device back to life after a system failure or to remove the software pre-installed by the manufacturer. Many users are afraid of this procedure, considering it too complicated and dangerous. However, if you strictly follow the algorithm of actions, the risk of damaging the gadget is minimal.
In this article we will look at how to flash an Android phone, step-by-step guide for which will be divided into logical steps. You will learn about preparing equipment, unlocking bootloader and directly installing a new operating system. It is important to understand that this action will void the warranty for the device in most cases.
The result of a successful operation will be a clean system without unnecessary junk or the ability to install a more recent version Androidif the manufacturer has stopped releasing updates for your model. Are you ready to take responsibility for your device?
Preparing the device and selecting firmware
Before starting any manipulations with the system partition, you must create a full backup copy of your data. The flashing process will inevitably lead to the complete deletion of all files, photos and contacts from the internal memory. Use cloud services or copy the data to your computer via USB cable.
A critical step is to find the correct system image file. Firmware for Samsung Galaxy S20 is not suitable for Xiaomi Redmi Note 10. An error in choosing a model can lead to your smartphone turning into a “brick.” You should look for files on the official websites of manufacturers or on reputable forums, such as 4PDA or XDA Developers.
Make sure that the battery charge is at least 60-70%. Process interruption due to low battery is one of the most common causes of fatal errors. You will also need a high-quality USB cable, preferably an original one, since cheap analogues often do not provide stable data transfer.
⚠️ Attention: Downloading firmware from random file hosting services without checking control bags can lead to the installation of malware or damage to system files.
Before downloading the firmware, check the device model code (for example, SM-G991B) with the name of the firmware file. Even one extra letter at the end of the name can mean a different region or processor modification.
Unlocking the bootloader
Most modern smartphones come with a locked bootloader. This is protection against unauthorized changes to system software. To flash the phone, this block must be removed. On devices Xiaomi this requires obtaining special permission through the utility Mi Unlock and waiting from 3 to 7 days.
Owners Google Pixel or OnePlus have an easier way. They just need to activate developer mode and allow software debugging. After this, the command in the mode USB. After this the command is in mode Fastboot removes the lock instantly, but all data will be deleted automatically.
The procedure usually looks like this: turn off the phone, hold down the combination of buttons (often Volume Down + Power) and connect the cable to the PC. The unlock command is entered in the terminal on the computer. The device interface will warn you about the loss of warranty and data.
- 🔓 Activate the "Factory Unlock" item in the "For Developers" menu.
- 💻 Install drivers ADB and Fastboot to the computer.
- 📱 Confirm unlocking using the volume buttons directly on the smartphone screen.
Nuances for Samsung devices
On Samsung smartphones, instead of the terminal, a combination of buttons is used in Download Mode (Volume Down + Up + Cable Connection). Confirmation is carried out by long pressing Volume Up.
Installing drivers and software
The computer should correctly recognize your device in special modes. Processors Qualcomm often require drivers Qualcomm HS-USB QDLoader 9008. For MediaTek drivers are required VCOM. Without them, the computer will not see the phone in firmware mode.
The choice of tool for recording the image depends on the chipset manufacturer and phone brand. A universal solution for many devices is a app SP Flash Toolthat works with chips MediaTek. For Qualcomm often used QFIL or QDLoader.
Owners Samsung will need a utility Odinwhich is the de facto standard for this brand. It has a specific interface with fields for different memory sections: BL, AP, CP, CSC. Incorrect distribution of files in these fields will make firmware impossible.
| Brand / Chipset | app for firmware | Connection mode |
|---|---|---|
| Samsung (Exynos/Snapdragon) | Odin3 | Download Mode |
| Xiaomi / Redmi (MediaTek) | SP Flash Tool | BROM / Preloader |
| Google Pixel / OnePlus | Platform Tools (ADB) | Fastboot / Bootloader |
| Qualcomm devices | QFIL / QPST | EDL Mode (9008) |
⚠️ Attention: On computers with Windows 10 and 11, you may need to disable driver digital signature verification to correctly install old or modified drivers.
Step-by-step guide for flashing firmware via Fastboot
Consider the universal method of flashing firmware via Fastboot, which is suitable for most devices with an unlocked bootloader. This method allows you to record partition images separately, which gives flexibility in configuration.
First place the image files (usually with the extension .img) in the folder with utilities Platform Tools. Open a command prompt in this folder. Make sure that the phone is in mode Fastboot and connected to the PC.
Enter the command to check the connection:
fastboot devicesIf you see the device serial number in response, the connection is established. Now you need to clear the old partitions before writing new data. This prevents version conflicts.
The process of recording a system image is as follows:
fastboot flash system system.imgIn a similar way, images of the bootloader (boot.img), recovery (recovery.img) and user data (userdata.img) are recorded. After completing all operations, enter the command fastboot reboot.
☑️ Checklist before flashing
Firmware via Recovery Mode (TWRP)
An alternative and more convenient way is to use custom recovery, such as TWRP. This method allows you to install firmware directly from a memory card or internal storage without using a computer at the installation stage.
First you need to install the recovery itself. Download the file twrp.img for your model and flash it with the command fastboot flash recovery twrp.img. After that, boot into recovery mode by pressing Volume Up + Power.
In the menu TWRP select item Wipe and swipe to clear data (Factory Reset). This is a required step when changing version Android or switching from one custom firmware to another. Then go to the section Install, select the archive with the firmware (usually .zip) and confirm the installation with a swipe.
The advantage of this method is the ability to install additional modules, such as Google Apps (GApps) or patches for obtaining root access (Magisk), immediately after the main firmware, without rebooting the system.
- 📂 Copy the firmware file to the internal memory of the phone.
- 🔄 Boot into TWRP Recovery.
- 🧹 Perform a complete data reset (Wipe Data/Cache/Dalvik).
- ⚡ Install the ZIP archive of the firmware via the Install menu.
Possible errors and ways to solve them
Even experienced users encounter errors. The most common is Signature Verification Failed. It occurs if you try to install official firmware through custom recovery or vice versa. The solution is to use a signature or disable verification in the TWRP settings.
Error Status 7 when installing via Recovery often indicates a mismatch with the Android version or processor type. Read the firmware description carefully: some images are intended only for devices with a chipset Snapdragon and will not work on Exynos.
If the phone is stuck on the logo after flashing the firmware (bootloop), try entering Recovery and doing Wipe Cache Partition and Wipe Dalvik Cache. If this does not help, you will have to repeat the firmware procedure from the very beginning, carefully monitoring the selection of files.
⚠️ Attention: If the device is no longer detected by the computer at all (black screen, no vibration), it may have gone into deep EDL mode (for Qualcomm) or requires memory resoldering. In this case, independent repair may be impossible.
In 90% of cases, firmware errors are caused by human factor: an incorrectly selected file, a bad USB cable or an interrupted connection during recording.
Will all information from the phone be erased during the firmware?
Yes, in the vast majority of cases, the firmware procedure involves completely wiping the partition userdata. All contacts, photos, applications and settings will be deleted. The exception is rare cases of updating “over” without a wipe, but this is not recommended when changing the software version.
Is it possible to flash a phone if it does not turn on?
This is possible if the device responds to connecting to a PC and enters the Download, Fastboot or EDL. If the phone does not show any signs of life (does not vibrate, the screen is black), then firmware is impossible and hardware repair is required.
What is the difference between Stock ROM and Custom ROM?
Stock ROM is the official firmware from the manufacturer, which guarantees stable operation of all functions, including the camera and NFC. Custom ROM is a modified version of the system (for example, LineageOS) created by enthusiasts. It can give a new version of Android for an old phone, but often has bugs in the operation of the camera or banking applications.
Do you need to connect the Internet during the firmware?
No, the process of writing files to the device occurs locally and does not require access to the network. The Internet is needed only at the stage of downloading firmware files, drivers and apps to the computer.