Are you a Vivo X20 and X21 (PD1709F / PD1728F) device user and facing issues with the invalid IMEI or unknown IMEI baseband? Then don’t worry. We got you covered. Here in this guide, we’ve provided the full guide on How to Repair unknown IMEI baseband on the Vivo X20 / X21 (PD1709F / PD1728F) device easily.

Now, talking about the IMEI (International Mobile Equipment Identity) number, it’s a unique 15-digit code that precisely identifies the device model whether you’ve used a SIM card or not. It’s worth mentioning that each and every IMEI number is unique and individually assigned to each and every mobile phone worldwide. You can also check the IMEI number on any phone by typing the *#06# on the dialer or Phone app.

We all know that a SIM card can be changed easily from a mobile phone. Therefore, the IMEI number comes in handy to track any particular device across the globe. Now, if you want to use a mobile device to use a SIM then it’s necessary to work the IMEI number properly. Meanwhile, the IMEI number can get corrupted or invalid or null while flashing any third-party firmware or any custom file on your device. Therefore, you should fix that issue for your Vivo X20 / X21 model.

Steps to Repair and Fix IMEI number on Vivo X20 / X21

Here you will get the easy guide to repair and restore the IMEI number on your Vivo X20 / X21 device by using the QCN Rebuilder Tool. This tool is free of cost and easy to use even if you’re new to this process. Now, before heading over to the guide, let’s follow all the requirements and download links below.

Now, let’s check out the download links and requirements below.

Pre-Requirements:

  • This guide and QCN file are for the Vivo X20 / X21 model only.
  • Your device should be charged up to 50% at least.
  • A PC/Laptop and a USB cable are required.
  • Keep a full backup of the device data before doing anything.
  • Enable USB Debugging. Check the video guide.
  • Download all the files and tools from above.

IMEI Rebuilding and Restore Guide

  • After downloading, install and run the QCN Rebuilder tool on your PC.
  • Click on Open file and select the Vivo X20 / X21 QCN file.
  • Now, replace the IMEI with the original IMEI number.
  • Click on Rebuild.
  • Next, connect your phone to a PC using a USB cable.
  • Open dial pad on your device and type this code ##717717## or *#558# to enable diagnostic mode.
  • If the above code doesn’t work, use CMD on your PC by following the commands below.

adb shell su setprop sys.usb.config rndis,diag,adb

  • Then run the QPST tool on your computer.
  • Click on the Restore tab > select the rebuilt QCN file > click on Restore.
  • You’re done.

That’s it, guys. We hope you’ve found this guide useful for your Vivo X20 / X21. If you’re facing any issues, feel free to ask in the comments below.

Download Files:

  • Download Flash tool: QPST or QFIL Tool
  • Vivo X20 / X21 QCN File (zip) – X21 Link | X20 Link
  • Download Vivo USB Drivers
  • Download QCN Rebuilder

Disclaimer: