Restoring IMEI on Android after flashing

The situation when it disappears after flashing the smartphone or resetting the settings IMEIis one of the most critical for the device owner. Without this unique identifier, the phone turns into a simple multimedia player: you will not be able to make calls, send SMS or use the mobile data, since the network simply does not see your SIM card. Often, users are faced with the fact that the settings display 000000000000000 or the field is completely empty, which indicates damage to the partition NVRAM or EFS.

The reasons for losing the identifier can be different: from the use of custom recovery and incorrect installation of firmware to virus attacks or experiments with rights. Root. Fortunately, in most cases the problem can be solved if you approach the matter carefully and use proven methods. Below we will look at action algorithms for different brands and universal methods of restoring communication.

Diagnostics of the problem and checking the IMEI status

Before taking active steps, you need to make sure of the exact nature of the breakdown. The fastest diagnostic method is to enter a special command in the dialer. Type *#06# and look carefully at the screen. If you see an error message or zeros instead of the 15-digit code, the problem is confirmed. It's also worth going to the menu Settings → About phone → Statusto see whether the SIM card is recognized by the system.

Sometimes the problem lies not in a software glitch, but in physical contact. Before getting into the software part, try removing the SIM card tray, wiping the contacts and inserting the SIM card back. Make sure that there are no processes in the task manager that block the operation of the radio module. If the phone was previously unlocked by the operator, re-flashing could reset these settings, requiring re-activation.

⚠️ Attention: If the IMEI disappeared immediately after an unsuccessful attempt to obtain superuser rights, the bootloader may have been damaged. In this case, recovery through standard methods may not work, and you will need to flash the stock image.

It is important to distinguish between a software failure and a physical failure of the board. If after all the manipulations the communication module remains inactive, the radio module chip itself or its harness may be damaged. In such cases, software methods are powerless, and the intervention of a service center with soldering equipment will be required.

Recovery through the engineering menu (MTK and general methods)

For processor-based devices MediaTek there is a built-in tool for manually recording identifiers. It can be accessed through the service menu. Dial the command ##3646633## or ##4636## in the dialer. If the menu has opened, go to the Connectivity or CDS Informationtab, then select Radio Information.

Here you will see a field for entering the AT command. To restore the first SIM slot, you must enter a command like AT+EGMR=1,7,"YOUR_IMEI_1". For the second slot, the parameter 10 is used instead of 7. After entering the command, press the Send ATbutton. The device must confirm the operation, after which a complete reboot will be required.

• 📱 Make sure that you enter the IMEI without spaces or extra characters, only 15 digits.
• 🔒 On some new versions of Android, access to the engineering menu is blocked by the manufacturer to increase security.
• 🔄 After entering the command, be sure to reboot the device for the changes to take effect.

It is worth noting that on modern smartphones with Android 10 and higher, this method often does not work due to changes in the security architecture. SELinux. In such cases, the system ignores AT commands if the device does not have an unlocked bootloader and superuser rights. If the menu does not open or the commands are not executed, proceed to more advanced methods.

Specifics of recovery on Samsung devices

Smartphones of the Korean giant have a unique file structure, where network data is stored in the section EFS. Losing this section is a common occurrence when installing custom firmware. To restore, owners Samsung often require a utility Octoplus/Octobox or specialized patchers, but there is also a free way through recovery mode.

Try resetting the network settings through the Samsung service menu. Dial #27663368378# (works on older models) or use the combination #197328640# to enter test mode. Here you can try to reflash the modem separately from the main system, using the file MODEM.bin through the app Odin. This is a safer method than a complete flashing.

Device model	Data section	Recovery tool	Difficulty
Samsung Galaxy S/Note	EFS / Persist	Odin + Modem File	Average
Xiaomi / Redmi	Persist / NV	QPST / Mi Flash	High
MediaTek (budget)	NVRAM	SN Write Tool	Low
Qualcomm (branded)	EFS / QCN	QPST QCN Writer	High

It is important to understand that flashing only the modem firmware will not affect your personal data, but may require unlocking the bootloader. If you do not have experience working with Odin, it is better to find a ready-made partition dump EFS specifically for your model and board revision on the network, although this carries the risk of installing other people's configurations.

Using the QPST and SN Writer utilities for advanced users

For smartphones on processors Qualcomm and MediaTek there are professional tools such as QPST (Qualcomm Product Support Tools) and SN Writer. These apps allow you to directly interact with the device's memory and record factory settings. To work, you will need installed ADB drivers and specific drivers for your chipset.

The process begins by putting the phone into download mode (Download Mode for MTK or EDL for Qualcomm). After connecting to the PC, run the utility and select the device port. In SN Writer you need to download the database file (Database File), which usually comes with the app or is downloaded for a specific model. Then enter the target IMEI and press the button Start.

⚠️ Attention: Using third-party utilities to record IMEI can lead to complete loss of warranty and “bricking” the device if there is an error in selecting the database file. Proceed only if you understand the risks.

The key point here is to have a file QCN (for Qualcomm) or a backup NVRAM. If you have a backup made before the firmware, the restoration will take a couple of minutes. If there is no backup, the app will try to generate a new identifier, but it may not be suitable for the frequencies of your region or may be blocked by the operator.

Recovery via ADB and backups NVRAM

The most civilized way is to restore from a backup made in advance. If you are a fan of experiments, you probably have a backup partition persist or nvram. To restore, connect your phone to a PC with USB debugging enabled and use the ADB console. The command for writing an image looks like adb push backup_file.img /dev/block/mmcblk0pXX, where XX is the partition number.

You can determine the partition number using the command adb shell cat /proc/partitions. Be extremely careful: writing to the wrong partition will permanently destroy the data. If you have rights Rootyou can use the terminal on the device itself and utilities like dd to copy memory blocks. This requires high qualifications, but gives the best results.

adb shell
su
dd if=/sdcard/nvram_backup.img of=/dev/block/bootdevice/by-name/modemst1
dd if=/sdcard/nvram_backup.img of=/dev/block/bootdevice/by-name/modemst2
reboot

If there is no backup, some users try to find “clean” dumps for their model on the network. This is a lottery: you can restore functionality, but get a conflict with Wi-Fi or Bluetooth MAC addresses, since this data is often stored in the same memory sections as the IMEI.

What to do if you do not have root access?

Without superuser rights, access to system partitions is denied. In this case, the only way out is to flash the stock firmware through the manufacturer's official software (MiFlash, Odin, SP Flash Tool), which can automatically recreate service partitions.

Prevention and creation of backups before flashing

The best treatment is prevention. Before any manipulation of the smartphone software, be sure to create a complete backup of critical sections. For devices with an unlocked bootloader, this can be done via TWRP Recoveryby selecting items Boot, System, Data and required EFS, Modem, Persist.

Save these files not only on your phone, but also in cloud storage or on your computer. Name the files clearly, indicating the model and firmware version. This will save you if the experiment fails. It is also recommended to write down the IMEI on paper, as the stickers fade over time and the boxes are lost.

Remember that modern smartphones are becoming increasingly closed systems. Manufacturers actively encrypt sections with personal data, linking them to a specific device. Therefore, there are fewer universal “magic buttons”, and the importance of individual backup is growing every year.

Frequently asked questions (FAQ)

Is it possible to restore IMEI without root access?

In most cases, on modern Android smartphones without superuser rights, restore IMEI is not possible, since access to system partitions is protected. The exception is some models with an accessible engineering menu, where recording is possible via AT commands, but this is becoming less and less common.

Is it dangerous to use someone else's IMEI for recovery?

Yes, it is extremely dangerous and illegal. Using someone else's ID may result in your phone being blocked by your carrier if a duplicate is detected on the network. In addition, you may unintentionally use the number of a device that is listed as stolen.

Why did the sound and Wi-Fi along with IMEI disappear after the firmware?

This is a classic symptom of partition damage Persist or EFS. These sections store calibration data not only for the modem, but also for sensors, audio chip and Wi-Fi module. Restoring this partition from a backup usually solves the whole range of problems.

Resetting to factory settings removes IMEI?

A normal reset through the settings menu (Wipe Data/Factory Reset) does not affect partitions with IMEI. The identifier disappears only when formatting internal memory sections (Format Data) or when installing custom firmware that does not work correctly with memory layout.

What is "Null Baseband" in the settings?

The message "Null Baseband" or "Unknown baseband version" means that the operating system cannot communicate with the radio module. This happens when the modem firmware does not match the Android kernel version or when the communication configuration files are damaged.