The firmware package available in this post is easily 'flashable' via sdcard.
This is official VDF 600 (Smart Prime 7 - ZTE) from ZTE Official webpage and it is shared here as is: without any modification whatsoever.
Before you flash this firmware package to your smartphone, be sure that it matches the model mentioned above.
- VDF 600 (Smart Prime 7 - ZTE) - Download
How to flash VDF 600 (Smart Prime 7 - ZTE) firmware
To flash this firmware package, follow the instructions here http://www.leakite.com/2016/09/how-to-flash-zte-stock-rom-firmware-via.html.