Owners of popular multimedia systems from the brand Junsun often face the need to update the device software. This may be caused by critical errors in the operation of the system, a desire to get new functions, or a complete loss of functionality of the head unit after unsuccessful experiments. The flashing procedure Android radios is significantly different from updating a smartphone, since here we are dealing with automotive electronics and specific firmware assemblies.
The process of restoring or upgrading software requires care and strict adherence to the sequence of actions. An error at any stage can lead to the screen going dark forever and the device turning into a useless brick. In this article, we will look in detail at how to determine the processor model, where to find the appropriate firmware, and how to safely install it into your system. Before taking active steps, it is important to understand that there is no universal firmware for all devices. Even two radios with the same model name, released in different months, may have different hardware. Therefore Junsun V1 or V2 Pro.
Before you take action, it is important to understand that there is no universal firmware for all devices. Even two radios with the same model name, released in different months, may have different hardware. That's why hardware identification is the first and most critical step on which the success of the entire operation depends.
Identification of the device model and processor
The most common user mistake is trying to install firmware downloaded by the model name on the box. In fact, Junsun uses many different platforms, such as Rockchip, Unisoc or MediaTek. To find out the exact configuration of your device, you need to go to the system settings and find the section with information about the software.
Go to the menu Settings → About device (or Car Settings → System Info). There are a few key parameters you should be interested in in this section. Write down or take a photo of the following details: MCU version number, Android kernel version, and most importantly the processor ID or build number. Often there is a code like MTK8227L or UIS7862.
⚠️ Attention: Never flash the device if you are not 100% sure that the MCU version and the processor match. Installing firmware from a different hardware platform is guaranteed to disable the radio.
If the standard menu does not open due to system errors, you can try using third-party diagnostic utilities, such as Device Info HW or AIDA64downloaded via a browser radios. However, in the case of a “brick”, this method will not work, and you will have to disassemble the device to visually inspect the chips on the board.
If the settings menu is not available, try connecting a USB keyboard and mouse. Sometimes this helps to bypass a frozen touch interface and get to the necessary sections to collect information.
After collecting information, compare the received data with firmware descriptions on forums or in technical documentation. Pay attention to the screen resolution, since the firmware for the screen 1024x600 will not fit the display 1280x720, which will lead to distorted or absent images.
Preparing tools and firmware files
To successfully install the new software, you will need a high-quality storage medium. It is recommended to use a USB flash drive with a capacity of no more than 32 GB. Large flash drives may simply not be seen by older versions of bootloaders, which will lead to a file reading error.
The file system of the drive must be formatted in FAT32. This is a critical requirement since the built-in Android bootloader in car radios often does not support NTFS or exFAT file systems. The formatting process can be performed on any computer through the standard disk management menu.
☑️ Preparation for firmware
The firmware should be downloaded only from trusted sources. The official website of the manufacturer, specialized forums like 4PDA or XDA Developers are the best places to search. Avoid dubious file hosting services where the file may have been damaged during download or modified by unknown persons.
After downloading the archive with the firmware, it must be unpacked. Inside you will find a file with the extension .img or .zip. Depending on your installation method, this file may need to be renamed. Most often, for automatic updating via Recovery, the file name must be strictly update.zip or auto_update.zip.
Why is it important to check the checksum?
Firmware files often weigh more than 1 GB. When downloading from the Internet, a data transfer error may occur. Checking the MD5 hash of the file ensures that the system image is complete and does not contain bad sectors that can cause a write failure.
Methods for installing firmware on Junsun
There are two main methods for updating software on devices Junsun. The first method is to update through the built-in Recovery menu, which is the most secure and recommended for ordinary users. The second method is to use a computer and special software to directly write the image into memory, which is required in case of serious failures.
The Recovery method is as simple as possible. You need to copy the firmware file to a prepared flash drive, insert it into the USB port of the radio and select the update option in the menu or reboot the device while holding down the Reset button. The system itself will detect the file and start the installation process.
If the radio does not boot at all, you will need a “blind” firmware method or use a UART-TTL engineering cable. This is a complex option that requires soldering and terminal skills. In this guide, we will focus on the software method via USB, which covers 90% of recovery cases.
| Update method | Complexity | Requirements | Risk of data loss |
|---|---|---|---|
| OTA (via Internet) | Low | Wi-Fi connection | Minimum |
| Local (USB) | Medium | FAT32 flash drive, file update.zip | Full reset |
| Via PC (SP Flash Tool) | High | Drivers, cable, skills | Critical |
The choice of a specific method depends on the current state of your device. If the system boots but is unstable, use a local update. If the screen is black and there is no response to the buttons, you will have to look for a service center or master the hardware firmware.
Step-by-step guide for flashing firmware via Recovery
First, make sure that the firmware file named update.zip is in the root of the flash drive. Do not put it in folders, the downloader may not find the path to the file. Insert the flash drive into the USB port, usually located on the front panel or via a separate cable.
Reboot the radio. In some models, to enter recovery mode, you need to hold down the Reset button (often recessed into the case) or a combination of the volume and power buttons when turned on. If everything is done correctly, a menu with several items in English or Chinese will appear on the screen.
Using the touch screen or a connected mouse, select item Apply update from ADB or Apply update from SD card. Confirm your choice by pressing Yes. The process of verifying the signature and unpacking the archive will begin. A progress bar will be displayed on the screen.
⚠️ Attention: It is strictly forbidden to remove the flash drive or turn off the car ignition during the recording process. Interrupting the power supply at this point will result in permanent damage to the bootloader.
After installation is complete, the system will prompt you to reboot. Select item Reboot system now. The first startup after the firmware can take from 5 to 15 minutes, as applications are optimized and new system files are created. Don't panic if the radio hangs on the logo longer than usual.
The first startup after the firmware always lasts longer than usual due to Dalvik/ART optimization. Wait until the desktop is fully loaded before starting setup.
Possible errors and how to resolve them
During the update process, users often encounter the message “Update failed” or “Signature verification failed.” The first error usually means that the firmware file is damaged or does not fit the given MCU version. The second error indicates that the firmware is not signed with the official developer key.
To solve the problem with the signature in some custom Recovery there is an item Install zip from sdcard -> Toggle signature verification. Disabling signature verification will allow you to install modified firmware. However, you should only do this if you are sure of the source of the file.
If the radio goes into a cyclic reboot (bootloop), try performing a full data reset (Wipe Data/Factory Reset) through the same Recovery menu. This will remove all user settings and applications, but may save the system from a software conflict.
In cases where the device does not respond to any actions and the screen remains black, the problem may be hardware. The eMMC flash memory may have failed or the voltage regulator may have burned out. Here software methods are already powerless.
What is Bootloop?
This is a condition in which the device constantly reboots before reaching the desktop. A common reason is a conflict in system libraries after an unsuccessful update or the removal of critical system applications.
System setup after update
After successfully downloading the new version of Android, you need to carry out the initial setup. First of all, check the touch screen operation and calibration. Go to Settings and find Factory Settings. To enter, a password is often required, which depends on the processor model.
Common passwords for accessing the engineering menu: 8878, 1234, 0000, 1617 or 5678. In this menu you can configure the type of car, the connection of the amplifier, the operation of the buttons on the steering wheel and the behavior of the button backlight.
Be sure to check the operation of the communication modules. Test Bluetooth pairing with your phone, Wi-Fi and GPS navigation. Sometimes after flashing the firmware, module drivers crash and you have to activate them manually in the corresponding sections of the settings.
⚠️ Attention: The interface and available settings may differ depending on the version of Android and the specific firmware build. If you are not sure of the purpose of a parameter in the engineering menu, it is better not to change its value.
For full navigation functionality, download offline maps and check satellite acquisition. If the GPS does not work, you may need to reconnect the antenna inside the instrument panel or configure the correct COM port in the navigation application settings.
Is it possible to flash the Junsun V1 with the firmware from V2?
No, this is impossible and dangerous. The V1 and V2 models use different hardware platforms and chassis. An attempt to cross-flash will damage the device.
What to do if the radio writes "No command" in Recovery?
Try pressing and holding the power button, and then, without releasing it, press the volume up button. This is a standard combination for entering the recovery menu on Android.
Will the firmware erase my music and memory cards?
The firmware only affects the system partition. Files on the internal memory (if it is separate from the system) and on the SD card should be saved, but it is better to make a backup copy of important data before starting.
Where can I download the original firmware for Junsun?
Original firmware can be requested from the technical support of the official store on AliExpress where the device was purchased, or found on specialized forums car audio.
Why did the sound disappear after the firmware?
The firmware may have been installed for a different amplifier configuration (for example, for external acoustics instead of built-in). Check the sound settings in the "Factory Settings" menu and select the correct output type.