| Issue | Probable Cause | Firmware-related Solution | |-------|----------------|----------------------------| | Bootloop after OTA | Corrupted cache partition | Flash only vbmeta , boot , cache | | IMEI = 0 | Lost nvdata partition | Restore backup of nvdata via upgrade tool | | No Wi-Fi / Bluetooth | Persist partition mismatch | Flash persist from same region firmware | | Stuck in emergency mode | Damaged bootloader | Reflash FDL1 + FDL2 + uboot | | FRP lock | Factory Reset Protection triggered | Flash patched vbmeta + boot with Magisk |
Download and extract the firmware package (usually a .zip or .pac file) to your PC. ZTE Blade V40 Design Firmware