If the phone still shows "Invalid SIM" after the unlock, check if the APN settings for your new carrier need to be entered manually.
A high-quality data cable to prevent connection drops.
Once the logs show "Unlock Done," disconnect the phone and restart it. Understanding NCK Dongle Download Links
Click on "Read Info" to verify the connection. The software should display the phone's IMEI and current lock status.
Change your USB port (use a Rear port if on a Desktop) or try a different USB cable.
In the software interface, navigate to the "Main" or "Service" tab. Select "ZTE" as the brand and "Z320" (or "Generic Qualcomm") as the model.
Unlocking the ZTE Z320 (also known as the ZTE Z-230 or ZTE Avid Trio) using an NCK Dongle is a reliable way to remove network restrictions. This process allows you to use the device with any compatible GSM carrier worldwide.