Losing the identification number of mobile equipment is one of the most unpleasant situations that a user of custom firmware may encounter. After an unsuccessful installation of third-party software or a failure during the update process, the phone stops seeing the SIM card, and the settings display the status null or a set of zeros instead of a unique code. This means that the radio module database has been damaged or overwritten, and now the device cannot register in the operator’s network.
Restoration IMEI is not a procedure for beginners, requiring accuracy, specific software and an understanding of the architecture of the radio module. Incorrect actions can lead to complete communication inoperability, and in the worst case, to the “bricking” of the smartphone. However, in most cases on processors MediaTek i Qualcomm data can be returned if you have a backup copy or the original number.
Before taking active steps, you need to make sure that the problem really lies in a software failure, and not in a physical breakdown of the antenna module. If the phone sees the network, but does not make calls, or does not detect the SIM card at all, the partition is most likely damaged. Next, we will look at the main methods for resuscitating identification data for different platforms. NVRAM. Next, we will look at the main methods for resuscitating identification data for different platforms.
Preparation and diagnosis of the problem
The first step is to accurately diagnose the condition of the radio module. You shouldn’t immediately rush to flash partitions without checking the current status. Enter the code *#06#into the dialing menu. If two identical numbers or the message “IMEI null” appear on the screen, then the data is lost. The check can also be carried out through the engineering menu or applications like Device Info HW.
⚠️ Attention: Before any manipulations, be sure to make a full backup of the system via TWRP Recovery. This will allow you to roll back changes if the process of writing data is unsuccessful.
For successful recovery you will need root access, since writing to system partitions without superuser rights is impossible. Make sure that the driver is installed on your smartphone ADB and USB debugging is enabled. The computer must have specific drivers installed for your chipset: MTK VCOM for MediaTek or Qualcomm HS-USB QDLoader for Snapdragon processors.
It is important to find the original number of your device. It is always indicated on the phone box, on a sticker under the battery (if it is removable) or on the warranty card. Write it down on paper, since you will have to enter the numbers manually, and an error in even one digit will make the phone invisible to operator databases.
☑️ Preparing to restore IMEI
Restoring IMEI on MediaTek processors
Chip-based devices MediaTek are the most common victims of IMEI loss, but they are also the easiest to restore thanks to the open architecture of the engineering menu. There are two main ways: using a mobile application MTK Engineering Mode or working through a computer with a utility SN Write Tool.
The fastest way is to use an application MobileUncle Tools or similar software installed directly on your smartphone. After launching the application, go to the Engineer Modesection, then select the Connectivity tab and find the item CDS Information. Here you will see fields for entering radio module data.
In the line Radio Information you will need to enter the AT command. The command format is strict and depends on whether you are restoring one slot or both. For the first slot, the command looks like AT+EGMR=1.7,"YOUR_IMEI_1", and for the second - AT+EGMR=1.10,"YOUR_IMEI_2". Please note that there should be no spaces between commas, and quotes are required.
Nuances of working with MTK Engineering Mode
On some versions of Android (especially 6.0 and higher), entering AT commands through the engineering menu may be blocked by the manufacturer. In this case, you will need to patch the build.prop file or use airplane mode when entering the command so that the radio module accepts the changes.
After entering the command, press the send button. If the system responded OK, reboot the device and check the code again *#06#. If the number does not appear, it is possible that the partition NVRAM is write-protected, and then a more complex method via a PC with administrator rights will be required.
- 📱 Make sure that the SIM card is inserted before entering commands, since the module must be active.
- 🔌 When using PC software, the phone must be detected in mode
Port, and not just as a drive. - 💾 Save the file
NVRAM.imgafter successful recovery on a cloud drive.
Firmware method via QPST for Qualcomm
Smartphones Qualcomm Snapdragon require a completely different approach. Here the engineering menu is often truncated, and the only reliable way is to use the software package QPST (Qualcomm Product Support Tools) in conjunction with the utility QCN Writer. This method involves writing a ready-made radio module configuration file.
The essence of the method is that you need to find the file .qcnthat corresponds to your phone model. This file contains not only IMEI, but also antenna calibration data, frequency bands and Wi-Fi/Bluetooth MAC addresses. The search for such a file is carried out on specialized forums, such as 4PDA or XDA Developers.
⚠️ Attention: Flashing someone else's .qcn file from another phone model can lead to loss of the 4G/LTE signal or complete failure of the communication module. Use the files strictly for your model!
The process begins by putting the phone in Diagmode. To do this, you often need to enter the code in the dialer, for example ##717717## or through the ADB command adb shell setprop sys.usb.config diag,adb. After connecting to the PC, the port should appear in the device manager Qualcomm HS-USB Diagnostics.
Run QPST Configuration, add a new port and go to QCN File Manager. First, make a backup of the current (even broken) state by pressing Backup. Then select the downloaded file .qcn and click Restore. The recording process takes several minutes, after which a reboot is required.
| Tool | Purpose | Difficulty | Risks |
|---|---|---|---|
| MTK Engineering | Inputting AT commands on the fly | Low | Minimum |
| SN Write Tool | Direct writing to NVRAM (MTK) | Medium | Medium |
| QPST + QCN | Image recovery radio module (QC) | High | High |
| Maui META | Working with the MediaTek database | Average | Average |
If the Qualcomm port is not detected, try disabling driver signature verification in Windows or using another USB cable that supports data transfer, not just charging.
Manually editing NVRAM files via terminal
For advanced users who do not trust graphical utilities or cannot find suitable software, there is a method of directly editing files through the terminal Android Terminal Emulator or connecting via ADB. This method is universal, but requires knowledge of hexadecimal editing and the structure of the Android file system.
Files storing IMEI are usually located in the /data/nvdata/md/NVRAM/NVD_IMEI/ or /persist/radio/directory. The exact path depends on the manufacturer and version of Android. Files have names like IMEI_SV or digital indexes. To work, you will need a file manager with access to Root, for example Root Explorer or MT Manager.
The algorithm of actions is as follows: find the files responsible for IMEI, copy them to your computer. Open them in a HEX editor (for example, HxD). You need to find the byte sequence corresponding to your IMEI and replace the current zeros or garbage with the desired numbers in HEX format. After saving, the file is uploaded back to the phone with the correct access rights (usually 660 or 644).
adb rootadb remount
adb push IMEI_SV /data/nvdata/md/NVRAM/NVD_IMEI/
adb shell chmod 660 /data/nvdata/md/NVRAM/NVD_IMEI/IMEI_SV
adb reboot
This method is dangerous because it is easy to violate the checksum of the file. If the amount does not match, the radio module will ignore the file when loading and reset the IMEI to null again. Therefore, the use of this method is recommended only if you have experience working with HEX codes.
Use of professional boxes and dongles
If software methods do not help, or the phone is locked to the operator and has complex bootloader protection, professional equipment comes to the rescue. We are talking about tools such as Octoplus/Octobox, Z3X Box, Chimera or UnlockTool. These devices cost money, but often come with a one-time license or rental.
Professional boxes can communicate directly with the phone's bootloader in EDL (Emergency Download Mode) or BROM, bypassing standard Android restrictions. They can subtract the original IMEI from the factory partitions, if they were not completely erased, or write a new one, recalculating the checksums automatically.
⚠️ Attention: Using paid software and “cracked” versions of IMEI recovery apps carries the risk of infecting your computer with stealth viruses that can steal your passwords from banking applications.
To work with such boxes, you often need to disassemble the phone and short-circuit certain contacts on the board (Test Points) to put the device into service mode. This requires soldering skills and precision. However, this is the only chance for phones with processors HiSilicon or new MediaTek with a protected bootloader, where standard methods are powerless.
Professional boxes are a last resort. They are effective where free software is powerless, but require financial investments and skills in working with hardware.
Legal aspects and risks of changing IMEI
It is important to understand that changing IMEI is not an absolutely legal procedure in many countries. The identification number is linked to the device in the databases of operators and law enforcement agencies. Changing this number could be seen as an attempt to hide a stolen device or bypass carrier blocking.
If you restore the “native” IMEI that was lost due to a firmware failure, you are essentially returning the device to its rightful identifier. This is an acceptable repair practice. However, if you try to register a number from another phone (for example, to unblock a network), you are violating the rules for using communication networks.
Telecom operators have implemented systems GSMA Device Check and analogues that track IMEI doubles. If two phones with the same number appear on the network, both devices can be blocked remotely. In addition, banks and applications with a high level of security can monitor changes in hardware identifiers and block access to accounts if a device is suspected of being spoofed.
⚠️ Attention: Legislation is subject to change. In some jurisdictions, even having equipment to change IMEI may be illegal. Always check the current laws of your country before carrying out such operations.
Frequently asked questions (FAQ)
Is it possible to restore IMEI without root access?
In 99% of cases this is impossible. Writing to the NVRAM partition or system files requires superuser rights. The only exception is some old Samsung or LG models, where specific engineering codes worked, but on modern Android this is not relevant.
What to do if after flashing the IMEI became null again?
This means that the NVRAM file was not written correctly or is protected from being overwritten during boot. Try the method with a professional box or find a dump of the NVRAM partition specifically for your firmware version and restore it via TWRP.
Does changing IMEI affect the operation of Wi-Fi and Bluetooth?
Yes, it can. The radio module configuration files (especially .qcn for Qualcomm) store the MAC addresses of all communication modules. If the recording is incorrect, you can lose not only your cellular connection, but also the ability to connect to your Wi-Fi router.
Is it safe to use applications from the Play Market to change IMEI?
No. Applications that promise to change IMEI without Root or through simple interfaces are most often fakes or malware. Real recording is only possible at a deep system level with administrator rights.
Can an operator unlock a phone by IMEI remotely?
The operator can block the phone using the IMEI blacklist if the device is reported stolen. Restoring or changing the number does not guarantee unlocking, since modern networks also monitor other device parameters (serial number of the board, IMSI of the SIM card).