When a phone undergoes heavy modification, such as flashing incorrect custom ROMs, corrupting firmware updates, or improper rooting, the EFS partition can become corrupted. This tool rewrites the network calibration data back to the device to restore network functionality. Key Features of QCN Tools
: Safely read the working network configuration from a live device and save it as a .qcn or .xqcn file.
(sometimes called a QCN Editor or Rebuilder) is used on a PC to open a backup QCN file. If your original IMEI was lost, you would enter the original IMEI number
Disclaimer: Modifying or altering an IMEI number to spoof a device identity is illegal in many jurisdictions. This guide is strictly for repair and restoration purposes using the device’s original, legally assigned IMEI found on its original box or battery compartment. Prerequisites Imei Qcn Tool Download
Note: If your device is not rooted, specific dialer codes unique to your manufacturer (e.g., Xiaomi, OnePlus, Vivo) may be required to open the hardware diagnostic menu.
Check your Windows . Under "Ports (COM & LPT)", you should see Qualcomm HS-USB Android DIAG alongside a assigned COM port number (e.g., COM3). Step 2: Modify the Donor QCN File
Before starting, ensure your phone battery is above 50% and you have a high-quality USB cable. Step 1: Enable USB Debugging and Diag Mode When a phone undergoes heavy modification, such as
(Note: Root access is usually required to trigger the diagnostic property. Alternatively, some brands use secret dialer codes like *#*#717717#*#* to toggle Diag Mode without root).
Extracts the working network configuration and RF parameters from a healthy device.
Click on the tab and ensure your phone's Diagnostic COM port is visible and active. (sometimes called a QCN Editor or Rebuilder) is
Writes a healthy QCN file back to a device suffering from network loops, null IMEIs, or baseband unknown errors.
Replace the placeholder text with your and IMEI 2 . Click Rebuild or Convert to save the personalized QCN file. Step 3: Wipe Corrupted EFS Data