( Vivo MTK 4G IMEI Repair by ISP)
Guide Step by Step
Connect ISP and take Nvdata + NVRAM + 1GB dump backup
Clean RPMB or erase RPMB counter (write 1–16MB of GP partition)
Write back the dump, then erase Nvdata, NVRAM, and other security partitions
Edit Nvdata with MDMFixTool
Write the edited Nvdata
Disconnect ISP, full flash or OTA update
Done! Your IMEI is successfully repaired!