This indicates the hardware calibration data was written, but the specific IMEI string is blank. You may need a hex editor or a premium service tool to manually input your factory sticker serials into the text field of the QCN file before flashing. If you want to troubleshoot further, tell me:

Install the official and Qualcomm HS-USB QDLoader 9008 Drivers on your computer.

Reinstall the drivers and ensure you are using a USB 2.0 port rather than USB 3.0.

Unlike older MediaTek devices where IMEI could be rewritten using simple engineering mode codes, Qualcomm-based Vivo phones store IMEI data in secure partitions like , QCN , or Persist . When you:

: On Windows 10/11, restart your PC while holding the Shift key. Navigate to Troubleshoot > Advanced Options > Startup Settings > Restart , then press 7 or F7 .

: Fixes "Invalid IMEI," "Null IMEI," or "No Service" issues.

GSM Mafia .com is a platform known for providing various services and files related to mobile device repair, including IMEI repair. For many devices, including Vivo phones, they offer files and tools that can be used to restore or change the IMEI.

Vivo V9 IMEI Repair Original File by GSMMafia.com: Ultimate Guide

Insert your SIM cards to verify network registration, signal bar stability, and 4G VoLTE data functionality.

Technicians download these files with the expectation that they will restore the device's ability to read SIM cards. However, it is important to note that these files often contain placeholder values (generic numbers) rather than the device's unique original numbers.

If the original IMEI is restored, your phone should now connect to the network. Troubleshooting & Important Notes